Tuesday, February 16, 2021

Rats exhibit behavioral biases similar to human investors, emphasizing the suitability of the rat stock market model to future work into the behavioral neuroscience of suboptimal financial decision-making

Huttunen, A. W., Reeve, H. M., & Bowman, E. M. (2020). Bull, bear, or rat markets: Rat “stock market” task reveals human-like behavioral biases. Journal of Neuroscience, Psychology, and Economics, 13(4), 204–229. https://doi.org/10.1037/npe0000133

Abstract: Investors often exhibit behavioral biases (e.g., loss aversion) that are putatively underpinned by mechanisms supporting reinforcement learning in the brain, which are largely evolutionarily conserved across mammalian species. Although previous research has demonstrated that rats, similar to humans, exhibit behavioral economic biases in certain contexts, asset market contingencies have gone largely unexplored. Thus, we developed an experimental “stock market”’ task in which cohorts of 4 rats drove asset prices up and down by selecting and subsequently buying, selling, or holding “stocks” to earn sweet liquid reward. Profits and losses were operationalized as reward volumes larger than and smaller than a reference volume of reward, respectively. Following a loss, rats moved more slowly to collect the reward and spent less time licking at the reward spigot, indicative of lower motivation to approach and “savor” a loss reward. Rats also tended to respond suboptimally following a loss, which corresponded to an increase in risk-seeking behavior characterized by a bias against the optimal “hold” option in that context. Rats’ choice of the sell option demonstrated a robust tendency toward realizing gains more quickly than losses, which is characteristic of the “disposition effect” in human stock markets. Our results indicate that rats exhibit behavioral biases similar to human investors, emphasizing the suitability of the rat stock market model to future work into the behavioral neuroscience of suboptimal financial decision-making.

The persuasiveness of a disregard for the truth

Bullshitting and persuasion: The persuasiveness of a disregard for the truth. John V. Petrocelli. British Journal of Social Psychology, February 16 2021. https://doi.org/10.1111/bjso.12453

Abstract: Although generally viewed as a common and undesirable social behaviour, very little is known about the nature of bullshitting (i.e., communicating with little to no regard for evidence or truth; Raritan Q Rev 6, 1986, 81); its consequences; and its potential communicative utility. Specifically, it is hypothesized that bullshitting may be may be relatively influential under specified conditions. Experiment 1 participants were exposed to a traditional persuasion paradigm, receiving either strong or weak arguments in either an evidence‐based or bullshit frame. Experiment 2 also incorporated a manipulation of a peripheral route cue (i.e., source attractiveness). Findings demonstrate that bullshitting can be an effective means of influence when arguments are weak, yet undermine persuasive attempts when arguments are strong. Results also suggest that bullshit frames may cue peripheral route processing of persuasive information relative to evidence‐based frames that appear to cue central route processing. Results are discussed in light of social perception and attitude change.

Wearing high heels consistently increased the models’ attractiveness, regardless of whether or not it decreased their natural difference from the theoretically optimal angle of lumbar curvature; both men & women showed this effect

Women Walk in High Heels: Lumbar Curvature, Dynamic Motion Stimuli and Attractiveness. Norbert Mesk et al. Int. J. Environ. Res. Public Health 2021, 18(1), 299; January 3 2021. https://doi.org/10.3390/ijerph18010299

Abstract: Previous studies have demonstrated that the angle of women’s lumbar curvature affects men’s attractiveness judgments of them. The theoretically optimal angle of lumbar curvature provides better resistance against both hyperlordosis and hypolordosis as biomechanical costs of a bipedal fetal load that could impair a woman’s fertility. Since men find this attribute attractive, women aim to emphasize it by wearing high-heeled shoes. The primary objective of the present study was to test this evolutionary hypothesis using short videos presenting women walking by the camera. In line with previous findings based on static stimuli (photographs), dynamic stimuli (videos) presenting women walking in high-heeled shoes were expected to elicit increased attractiveness ratings as compared to women wearing flat shoes, which would be associated with the angle of lumbar curvature. Videos were taken of 52 female models walking in two conditions (i.e., wearing either high-heeled or flat shoes). A total of 108 participants (61 males, 47 females) rated the walking models’ physical attractiveness in an online setting. Each model’s lumbar curvature was measured both in high heels and in flat shoes using photographs taken of them prior to each video recording. The results showed that wearing high heels consistently increased the models’ attractiveness, regardless of whether or not it decreased their natural difference from the theoretically optimal angle of lumbar curvature. Both male and female observers showed this positive effect. Furthermore, a negative correlation was found between the models’ body mass index (BMI) and their perceived attractiveness scores in both conditions.

Keywords: lumbar curvature; high-heeled shoes; attractiveness; mate choice preference; dynamic/video stimuli

The Contribution of Sex to Quality of Life in Modern Societies: Is Sex Distorted in Modern Societies?

The Contribution of Sex to Quality of Life in Modern Societies. Bjørn Grinde. Applied Research in Quality of Life, Feb 15 2021. https://rd.springer.com/article/10.1007/s11482-021-09926-6

h/t Rolf Degen: https://twitter.com/DegenRolf/status/1361614638568398851

Abstract: Sexual behavior is a core activity not only for our genes, but also for individual happiness. It is therefore important to assess how this aspect of life functions in industrialized nations. Adopting the idea that society should aim at maximizing happiness, the question is whether the present situation is optimal, or if we should strive toward cultural changes that may improve the impact of sex. Sex is associated with some of the strongest rewards the brain has to offer, and consequently should serve to improve quality of life. There are, however, numerous pitfalls in that sex easily elicits negative emotions. Certain aspects of sexuality may reflect what is referred to as a ‘disease of modernity’; that is, the present environment is causing an increase in the prevalence of sex-related misery. The text use both an evolutionary and a bioecological perspective to understand human behavior. Biological (nature) and ecological (environment or nurture) factors are considered in order to assess how to improve the impact of sex on quality of life.

Is Sex Distorted in Modern Societies?

Sexual Behavior

A key question for the present analysis is whether the present ecological setting for human development cause sexual behavior to be skewed in a negative direction. Is the emotional burden associated with sex higher today than what one would expect was the case in the EEA? The question will initially be probed in two ways: I shall consider possible changes in sexual preferences; and look at sexual dysfunctions. As to putative changes, both cross-cultural comparison of traditional societies and observations of animal behavior are relevant. The subsequent discussion on possible contributing mismatches adds pertinent information.

It should be kept in mind that what is considered troublesome in the present analyses, is not whether the behavior has changed, is odd (in a statistical sense), or off (in the sense of not contributing to procreation). The issue is whether the present situation is suboptimal as to quality of life. Aberrant behavior is, however, likely to impede happiness. Most societies have ideas as to what is considered proper sexual conduct. When individuals transgress these lines, they tend to be antagonized; a situation that easily leads to negative emotions. In other words, abnormal sexual behavior often has a negative impact on happiness, but the problem may be ameliorated by changing the attitudes in that society.

As the primary function of sex is propagation, sexual desires should be directed at coitus. According to anthropological literature (Ford and Beach 1951), coitus is indeed by far the most common practice; yet, in most cultures there appear to be a reasonable amount of sexual activity that is not aimed at fertilization. In a species using sex to enhance bonding, sex without pregnancies serves a genetic purpose; thus the use of contraceptives, or interrupted ejaculation, should be considered normal. Moreover, as sex is strongly reward-driven, one should also expect that self-stimulation occurs. This is indeed the case, based on the anthropological descriptions of tribal people as well as observations of other species of mammals (Ford and Beach 1951). Most traditional cultures are well aware of the possibility for self-stimulation; the practice is typically not banned, but discouraged as being less desirable.

Aberrant Practices and Desires

Certain sexual behaviors and desires may reflect a distorted sex module. The more common examples are discussed below.


Self-stimulation probably occurs in all cultures, but in industrialized countries it stands for a considerable proportion of sexual activity (Prause 2019; Regnerus et al. 2017). It seems likely that the present situation represents an increase compared to tribal societies. The increase is presumably at least partly driven by the opportunities offered by pornography, particularly in the form of Internet-based sexual stimuli, but perhaps also by a lack of sexual partners or frustrations associated with intimate relations. Stone Agers would most likely take an interest in porn; in fact, even male macaques willingly ‘pay’ for viewing pictures of female macaques in heat (Deaner et al. 2005).

The question is whether the use of pornography, and the concomitant high prevalence of masturbation, affect current sexual behavior in ways that are undesirable. Although masturbation does offer sexual pleasures, and therefore contributes to happiness, the practice may have negative effects on emotional life. For one, the focus on self-stimulation may imply less focus on sex with a partner, which could reduce the strength of a relationship; and two, depending on the kind of stimuli sought, it could cause the sex module to develop in adverse directions. For example, if a person focuses on violence or on underage females, the desires may move further in this direction; that is, masturbatory fantasies about a stimulus can reinforce and broaden that form of arousal (Nolen-Hoeksema 2013).

Types of Stimuli – Paraphilics

Another pertinent question as to aberrant sexuality is what sort of stimuli trigger sexual arousal. There is a wide range of interests, most, if not all, are catered to on Internet (although legal issues cause some to be less readily available). The more common search words concern what may be considered normal sexual interests (Ogas and Gaddam 2011; Salmon and Fisher 2018; Tyson et al. 2015): Men search for young and willing females with sexual appeal. As pointed out above, a virgin look is preferred, but there is also a desire for older women, often aimed at those already with a partner. Married females make sense as a strategy for men; if the woman gets pregnant, his genes will be passed on with a minimum of investment.

Although the majority of attention is in line with what one would expect reflects innate tendencies, there is also considerable interest in porn (and real-life experience) for sexual content that is less likely to reflect biology. Examples include fetishes for dead bodies, feet, animals, or female clothing items. Obscure preferences are referred to as paraphilia. Although a range of ‘odd’ sexual behavior has been observed in animals, including attempts to have sex with dead bodies, at least for animals living in the wild this seems to reflect a spillover of sexual urges rather than a prime interest. Moreover, paraphilia seem to be rare in the anthropological literature on tribal societies, thus the present prevalence is likely a consequence of the modern environment.


Some homosexual activity (not counting mock-mounting as used to confirm social rank) is apparently the norm in mammals, and particularly so in species lacking the pheromone associated TRPC2 gene; that is Old World monkeys, apes and man (Pfau et al. 2019). Yet, heterosexual behavior dominates – with the possible exception of bonobos (de Waal 2007). Exclusively homosexual individuals seem to be extremely rare in mammals, at least in the wild, thus the observed homosexual behavior is typically a question of bisexuality. Humans have a relatively high rate of bisexuals (5–20% depending on gender and how the issue is probed), but more peculiar is the observation that approximately 1% claims to be solely interested in one’s own gender (Savin-Williams et al. 2012; Tyson et al. 2015). The question of whether the prevalence is higher today than in the EEA is difficult to resolve due to the impact of cultural norms.

Two factors may explain why homosexual activity is relatively common in our species. One is the fact that we probably have a particularly strong sex drive, due to the dual purpose of sex; and a strong drive seems more likely to include aberrant behavior. The other is that humans, as in the case of bonobos, have extensive collaborations with individuals of the same gender. One would expect homosexuality to serve a role in bonding, a phenomenon that may appear in other species as well (Douglas 2009; Packer and Pusey 1987). The relatively high prevalence of exclusive homosexuals may reflect aspects of the present environment; for example, condemning the behavior may create a need to ‘choose side’.

Trannies, or shemales, are men with penises, but female appearance and often breasts due to surgery or hormone treatment. Contrary to popular belief, trannies cater primarily to heterosexual (or bisexual) men, and is one of the more popular categories of porn on the Internet (Ogas and Gaddam 2011). In fact, many men take an interest in penises; ‘big cock’ rates among the most popular search terms, and the popularity cannot be explained solely by searches made by females or gay men (Salmon and Fisher 2018). The popularity possibly reflects that bisexuality is a common feature, perhaps one that is more oppressed than expanded in industrialized societies.


Taking and interest in adolescent females, as long as they have anatomical features suggestive of maturation, is biologically normal. An interest in infants is not. Related behavior have been observed in other mammals such as the Hawaiian monk seal (Hiruki et al. 1993), but it appears to be rare with the exception of bonobos (de Waal and Lanting 1997). Both heterosexual and gay human males take an interest in juveniles. In an Internet-based, anonymous questionnaire, 4.1% responded that they had sexual fantasies about children, and 3.2% admitted to having abused infants (Dombert et al. 2016). Based on the interest in search words such as Lolita and preteen, this may be an underestimate of the true appeal of children as sexual objects (Hald and Štulhofer 2016).

In many tribal societies, it is common for parents to fondle the genitals of their infants (Ford and Beach 1951). In the present perspective, this practice should not be considered pedophilic, as it typically does not imply sexual arousal for the adult. There are rare examples of traditional cultures that not only allow, but encourage sex between adults and infants (Ford and Beach 1951; Kelly and Lusk 2013). The considerable interest in modern societies, in spite of the ostracism, suggests that the practice resonates with some innate urges – perhaps a trait shared with bonobos. Yet, the prevalence may have increased due to mismatches in the present environment. As the practice is unlikely to gain acceptance, pedophilic desires are expected to decrease quality of life.

‘Rough’ Sex

Rape-like behavior occurs in many species (Smuts and Smuts 1993). Whether the species form parental couples or not, it makes evolutionary sense for the male to force himself upon the female. Humans may be the expert rapist in that we have hands to hold the victim and language to form oral threats. Not surprisingly, rape is common both in the tribal setting and in modern societies (Ford and Beach 1951). Although the use of force can be construed as normal male sexual behavior, it constitutes a minor part of all sexual encounters.

As to the question of happiness, the use of force on a non-conforming partner is likely to imply a heavy load of negative feelings for the victim, and should thus be discouraged. The interesting observation is that both genders willingly participate in activities involving violence or coercion, as exemplified by the popularity of concepts such as bondage, spanking, dominance, rough sex, slave, sadism, and masochism (Ogas and Gaddam 2011). There is limited evidence for similar interests in tribal societies, except that inflicting pain (typically in the form of scratching and biting the partner) is considered to enhance sexual pleasure in certain cultures (Ford and Beach 1951). The more overt forms of violent, voluntary sex seem to be novel, which suggests that the practice, or at least the prevalence, is a consequence of the present environment.

Presumably, the participants derive pleasure from rough sex that goes beyond what they would obtain from normal sex. As previously pointed out, many brain modules can activate either pleasure or pain. Even the sensory signals stemming from pain receptors can be converted to yield pleasure, as observed when people take delight in self-harming (Edmondson et al. 2016). Thus, pain may enhance the sexual experience. Similar arguments can be made for submission and dominance in that these situations too can activate rewards rather than their expected (emotional) pain. Moreover, it has been suggested that women may appreciate (mock) rape for the experience it offers of being attractive (Hazen 1983).

Sexual Dysfunctions

The main category of sexual disorders is sexual dysfunctions. The more common forms concern problems like premature ejaculation, lack of erection, and lack of libido. Based on reports from Western countries, the conditions affect some 30% of adult men and 40% of adult women (Lewis et al. 2004; Shifren et al. 2008; Laumann et al. 1999). Although there is not much in terms of comparable anthropological data, the above figures suggest that the present environment is responsible for an increase. It seems unlikely that evolution would design a sex module that malfunctions in such a large proportion of the population.

Hypersexuality, or sex addiction, is recognized as a problem, but not included in diagnostic manuals. The existence of sex addiction is in line with general assumptions as to addiction. Any stimuli that engage the reward modules of the brain are likely to cause some form of addictive behavior when amply available, sex-related stimuli on the Internet should be no exception. Sex addiction has a negative impact on happiness if the behavior is excessive in a way that is unfavorable for other aspects of life. Some people do consider their own craving for sex to be troublesome in that it may, for example, damage career or personal relations (Griffiths 2012). It seems unlikely that sexual addiction was conceived as a problem in the EEA.

Conclusion as to Sexual Distortion

Based on the above discussion, it seems likely that the modern environment does increase the prevalence of abnormal sexual desires and behavior. As pointed out above, the question is not whether a behavior is aberrant, but how it serves the overall happiness of the population. As long as sexual practices involve consenting adults, they have the potential to enhance happiness. Yet, one would expect that it is easier to achieve sexual satisfaction for the average person if he or she has a sex module that functions according to cultural norms.

Animals in captivity often display abnormal sexual behavior; for example, dogs are known to mate with human legs, zoo animals to chase away potential partners and refuse to mate. We live in a ‘human zoo,’ in the sense that the environment includes likely negative mismatches; their presence is expected to impair mood and cause unpredictable behavior (Grinde 2009a; Hidaka 2012; Nesse 1999). That is, the ‘zoo’-situation implies an ecological setting that promotes aberrant sexual desires, a lack of interest in sex, and an increase in hostility – in both animals and humans.

Negative emotions evolved for a purpose, the problem is when the relevant modules are active without serving that purpose. Anxiety, for example, can be construed as unwarranted activity of the fear module; while depression reflects similar hyperactivity of a low mood module (Grinde 2012). Clinical anxiety and depression are each diagnosed in some 10–20% of the people in Western countries (Moffitt et al. 2010; Wittchen et al. 2011); moreover, the diagnosable disorders are likely only the tip of the iceberg as to reduced quality of life, perhaps most people suffer from unnecessary worries and ruminations. It seems unlikely that these mental problems were equally common in the EEA as one would expect evolution to select against excessive negative emotions (Grinde 2005). People who associate sex with negative emotions appear to have reduced sexual desire (Woo et al. 2011); a situation that certainly is not in the interest of the genes.

Based on the discussion so far, I infer that the happiness of the population should improve if we can identify, and restore, relevant mismatches. It is a question of examining the ecological systems that shape the human mind (Bronfenbrenner 1989).

Possible Mismatches


Social structure has changed drastically since the EEA. Humans moved from a tribal setting to large-scale societies. Today we regularly interact with a considerable number of strangers, and many people lack a close-knit social network. The situation is likely to include negative mismatches and concomitant stress (Grinde 2009b). Moreover, the loss of tribal social bonds may explain the success of religions with strong moralizing gods (Grinde 2011). Sexual moral is still a significant factor of the macrosystem in most Western societies, exemplified by the restriction on nudity and sex in films. Compared to the more lenient censor regarding violence, which is behavior one ought to avoid, the censor on sex, which is behavior with a lot of positive potential, may seem strange. One possible explanation is that the sexual urges are more in need of being subdued in a large-scale society; that is, sex is a more permeating feature of the mind.

In the EEA, up until the last 50–100 thousand years, people were probably mostly naked (Kittler et al. 2003). Although various rules regarding touch and sexual relations apply in tribal societies as well, these cultures tend to be more relaxed than industrialized nations as to both dress codes and sexual behavior (Ford and Beach 1951). It seems likely that the default setting for humans is an open and permissive attitude to nudity and sex, as it is in animals.

Relationships – whether it is with a sexual partner, relatives, or friends – are important for the genes. Consequently, the relevant emotional modules offer strong rewards, but also considerable punishment. The punishment is primarily meant to induce people to cater to their relations. That is, negative emotions are there to warn you against something that, in the EEA, could be very destructive for the genes, such as being banished from the tribe or losing a partner. A strict sexual moral will tend to elicit more of these emotions and can therefore have a considerable negative impact on happiness.

Restrictions on Infant Sexuality

When looking for relevant mismatches affecting the mind, it makes sense to focus on the environment of infants, as the brain develops proportionally more in the first years of life (Bronfenbrenner 2005). One facet of the microsystems affecting children in modern societies may be particularly destructive; that is, the restrictions on children’s experience with nudity and sex. Parents typically hide their sexual activity, and their nude bodies, not just for other adults, but also for their children. In other primates, sex is generally not concealed, and the anthropological literature suggests that the same was the case in the EEA (Ford and Beach 1951; Frayser 2003; Josephs 2015).

As reviewed elsewhere (Josephs 2015), infants take extensive interest in their genitals, as well as those of others, and they obtain pleasure from genital stimulation from a very early age. Moreover, those with frequent exposure of this sort, even if the exposure comes in the form of abuse, tend to be more sexually active later in life (Browning and Laumann 1997). The lack of sexual stimulation and experimenting in present society may contribute to a situation where sex does not fulfil its potential for enhancing happiness. Besides restricting sexual rewards, the situation is likely to increase the level of negative emotions such as guilt, shame, and regret.

It appears to be normal for children to enact sex play with peers from as early as 3 or 4 years of age (Kinsey et al. 1998; Martinson 1976). In fact, boys at this age may experience a sort of ‘orgasm.’ The Human Relations Area Files include several cultures where children learn sex through observations and play (Ember and Fischer 2017), much as they learn about other aspects of adult behavior. Infants explore the genitals of their parents, and mothers stimulate the genitals of their children, either for pleasure or for soothing and comfort. Juvenile sexuality also seems to be the norm among other primates, although males may engage in this sort of behavior more often than females (Dixson 2012). Juvenile male chimpanzees mock mate with any female that allows them, including their own mothers (de Waal 2007). This opportunity to learn about sex, and develop a suitable attitude, is generally absent in modern humans. On the contrary, children typically learn that nudity and sex is taboo.

The observation that the genitals can offer pleasures even in infants, rather than having this trait develop at puberty, is an important aspect of human biology, and thus an integrated part of the infant ecosystem. The observation substantiates the idea that children are meant to engage in sexual play. In contrast, the female nipples do not seem to become particularly erogenous until the development of breasts (Robinson and Short 1977).

Mental functions, including the sex module, are meant to develop in interaction with the ecological setting. In mammals such as goats and sheep, and possibly in humans, males are imprinted as to sexual interest during adolescence (Ogas and Gaddam 2011). In fact, there appear to be a critical period for males to develop sexual desires (Ford and Beach 1951). Chimpanzees that are refused sexual play during infancy, later struggle to perform sexually (Yerkes and Elder 1936). When the environment differs substantially from the EEA, the desires and the emotional reactions are likely to become distorted.

Sexual Stimuli

As suggested above, another consequence of large-scale societies was the introduction of dress codes so that men would be less inclined to desire, and consequently abuse, women. Internet has made sure that there is abundant alternative stimuli available. Both the lack of natural nudity and the profusion of stimuli are mismatches with a potential for negative effects.

The impact of Internet porn is discussed above. One additional problem is that the high standard of the models presented, whether catering to males or females, make it more difficult to enjoy normal sexual stimuli – that is, less perfect bodies and less ideal male characters. The consequences may include unwarranted negative feelings when women assess their own bodies, and lack of sexual fulfilment for both if a person does not find the spouse sufficiently attractive.

It seems reasonably well documented that the use of Internet porn can contribute to sexual dysfunction (Park et al. 2016). What typically happens is that the user, more often a male, masturbates to porn that, (1) offers unlimited access to ‘novel and ideal sex objects’; and (2) caters to peculiar preferences. The combination implies a form of superstimuli not found in real life, and consequently the person may experience erectile dysfunction, lack of libido, or low sexual satisfaction when with a partner. One may argue that the potential for sexual pleasures is catered for by masturbation, but the bonding part and the skin-to-skin contact is missing.

A Minority of One against a Majority of Robots: Robots Cause Normative and Informational Conformity

Nicole Salomons, Sarah Strohkorb Sebo, Meiying Qin, and Brian Scassellati. 2021. A Minority of One against a Majority of Robots: Robots Cause Normative and Informational Conformity. ACM Trans. Hum.-Robot Interact. 10, 2, Article 15 (February 2021), 22 pages. https://doi.org/10.1145/3442627

Abstract: Studies have shown that people conform their answers to match those of group members even when they believe the group's answer to be wrong [2]. In this experiment, we test whether people conform to groups of robots and whether the robots cause informational conformity (believing the group to be correct), normative conformity (feeling peer pressure), or both. We conducted an experiment in which participants (N = 63) played a subjective game with three robots. We measured humans’ conformity to robots by how many times participants changed their preliminary answers to match the group of robots’ in their final answer. Participants in conditions that were given more information about the robots’ answers conformed significantly more than those who were given less, indicating that informational conformity is present. Participants in conditions where they were aware they were a minority in their answers conformed more than those who were unaware they were a minority. Additionally, they also report feeling more pressure to change their answers from the robots, and the amount of pressure they reported was correlated to the frequency they conformed, indicating normative conformity. Therefore, we conclude that robots can cause both informational and normative conformity in people.

CCS Concepts: • Human-centered computing → Empirical studies in HCI; • Applied computing → Psychology; Additional Key Words and Phrases: Human-robot interaction, peer pressure, informational conformity, normative conformity


Previous results have shown that robots are capable of causing adult conformity [2436]. In this section, we discuss how robots in our study were causing normative conformity in addition to informational conformity. We also discuss how different tasks affected the conformity rates in human-robot interaction. Last, we discuss some potential future directions.

5.1 Informational Conformity

We believe robots were causing informational conformity due to three main reasons. First, when participants were given more information about the robots’ answers, they conformed significantly more. Second, participants viewed the robots as being capable of this task, which is an element that enables informational conformity. And third, the subjective nature of the task increases the willingness to accept information from the robots, which was confirmed by many participants in the open-ended question.

To measure whether robots were causing informational conformity, the current analysis focused on the quantitative, selected, and blind conditions, where the amount of information given to the participant varied. Participants conformed significantly more in the quantitative conditions than they did in the blind and selected conditions. Even though participants in the selected condition did conform a higher number of times on average than the blind condition, this difference was not significant, implying that being aware that at least one robot chose a different answer was not sufficient to sway the participant to change their answer. However, when the participants were aware that all the robots chose a different answer than they did, they more frequently conformed to the robots. The results suggest that having the information that one was in the minority in his/her answer increased the likelihood of accepting information from the majority as the participants had more information from the environment to make decisions [41].

One of the factors that is believed to influence informational conformity is the expertise of the group [1044]. Participants viewed the robots as performing well at this particular task: in the questionnaire, participants rated the robots as being similar to themselves at how good the robots were at the game. These results are surprising, considering robots do not usually perform well at high-level tasks such as understanding the meanings of images. Additionally, participants gave similar scores to the robots’ capabilities across the conditions, indicating that they are not viewing the robots as better at the game in one condition compared to another. However, participants conformed more in the quantitative condition compared to the selected and blind conditions. Once participants were given more information (such as how many robots chose each answer), they utilized this information and conformed to the robots. This indicated that participants believed the robots to have the correct answer but only had sufficient information to conform in the conditions with more information.

One of the main factors that influences informational conformity is uncertainty in the answer [11]. Individuals are more likely to copy others when they are uncertain [40]. Therefore, it was likely that the subjective nature of the game increased the participants’ likelihood of accepting information from the robots. Our results are in line with how participants responded to the open-ended question, where they frequently stated they were using the robots’ answers to decide their own final answer. For example, one participant in the quantitative condition wrote: “Yes, from life experiences, majority is usually correct.” Another participant in the quantitative condition wrote: “Yes, because I thought the way they decided was going to be right.” There were also participants in the selected condition who responded that they changed their answer due to information of the robots’ answers: ‘When they highlighted a different option, and then I felt that it was more apt than the one I chose.”

5.2 Normative Conformity

Our results show that normative conformity was playing a role in the participants’ decisions to conform to the robots in the staring and quantitative conditions: participants conformed significantly more in critical rounds in the staring and quantitative conditions compared to the other rounds. Participants reported feeling pressure to change because of the robots and acted upon it. Additionally, participants in the selected and blind conditions that did not have the information to conform during critical rounds changed their answers frequently to the answer of at least one of the robots in the next round.

To measure whether robots were causing normative conformity, this analysis was focused on the comparison of the staring, quantitative, and selected conditions (as in the blind condition, participants had no information on the robots’ answers, and therefore normative conformity was highly unlikely). In the quantitative condition, there were significantly more changes in participant answers during critical rounds than in the selected condition, demonstrating that being aware of the number of robots choosing certain answers influenced participant's decisions to conform. Therefore, being aware that one was in the minority in a group of robots increased the likelihood of conforming to them, compared to only knowing that at least one robot chose a different answer.

Participants in the staring, quantitative, and selected conditions were making, on average, a similar number of changes across all the rounds (critical and non-critical). However, participants in the staring and quantitative conditions were making many more of these changes in critical rounds. Providing participants with the information of how many robots chose each card did not increase overall changes but specifically increased the number of changes to the robots in the rounds where they were the minority. This is in line with previous research showing that having a unanimous group increases normative conformity [2].

There were no significant differences in the frequency of conformity between the staring and quantitative conditions. Therefore, adding the staring behavior did not significantly increase conformity. There are multiple possible interpretations of this. The first being that participants did not feel additional peer pressure because of the staring behavior either because it was not very observable or because they did not perceive it as a persuasive behavior. Another interpretation is that the quantitative behavior alone was already causing a large amount of peer pressure, and adding the staring behavior did not increase the frequency of conformity significantly. A previous study has shown that eye contact can actually create resistance to the person who is trying to persuade [9]; therefore, the staring behavior might have caused some participants to conform less. An additional possibility is that the staring behavior is causing psychological reactance in some of the participants towards the robots. Studies have shown that very apparent persuasive behaviors can decrease the amount of compliance [21]. Additional studies should be conducted to determine which social behaviors of robots cause increased peer pressure.

Participants in the staring and quantitative conditions were making most of their changes in critical rounds, whereas participants in the selected and blind conditions were frequently changing their answers in the round right after the critical round. Participants in the selected and blind conditions did not have the necessary information to see they were a minority in the critical rounds in time for them to change their answers. However, when the final answer was shown, the participants observed that all the robots had chosen a different answer than they did. We believe this caused the participants in these conditions to change their answers in the following round, attempting to choose the same answer as the robots. Additionally, the robots getting the answer right or wrong in the critical rounds did not appear to play a role in deciding to change their answer in the subsequent round. Therefore, the main reason they were changing their answer was not necessarily because they thought accuracy would be increased. Instead, we believe this was an indication of normative conformity where participants wanted to be in-group with the robots.

Participants in the staring and quantitative conditions reported higher pressure to change their answers because of the robots than the selected and blind conditions. Additionally, the amount of pressure to change was correlated with the number of critical round changes. This was an indication of normative conformity, where participants were feeling pressure to change and acting upon that pressure. Participants in the staring and quantitative conditions also mentioned feeling peer pressure in the open-ended question. Several participants commented that they changed their answers to match the robots’ answers when they were part of the minority, indicating that participants were changing to become part of the majority. For example, one participant in the staring condition wrote: “Yes, because they'd look at me judgmentally when I had a different answer, so it made me doubt myself.” Another participant in the staring condition commented: “Sometimes when they all chose the rose field, I felt dumb for picking the ballet shoes.” A participant in the quantitative condition wrote: “Yes (I changed) if they outnumbered me on one particular picture.”

5.3 Influence of Task in Conformity

Several studies have been conducted attempting conformity with robots, of which some observed conformity [243643] and some did not [5739]. The main difference between the experiments which observed conformity and those which did not was the task being tested. It is necessary to have a task where the participant is not certain of the correct answer. The robotic studies which failed to show conformity mostly tested Asch's line task, which has a clear, correct answer, whereas the studies which did show conformity with robots had a task in which the answer was not as clear. Our study used a subjective word-card matching task. Hertz and Weise [24] presented the questions to the participants for only 2.5 seconds and the accuracy rate of responding solely was 63% for the analytical task and 68% for the social task. Similarly, the tasks of Williams et al. [43] used socio-conventional and moral questions. Therefore, we believe it is necessary to have a more subjective task to cause conformity. This is in line with human psychology, where more difficult and subjective tasks have higher rates of conformity [3].

Other characteristics of our task that could have influenced the number of times participants conformed were that they were all sat at the same table close together [30] and that the answers were publicly shown on a shared screen [16]. Additionally, the answers of the robots were highlighted on the screen, focusing the participants’ attention on those answers, which could have influenced conformity [10].

5.4 Future Work

There are several different areas of potential future work, following our results. The robots used in the study were very simple, but despite their size and simplicity, they caused both informational and normative conformity. Factors that increase informational conformity are the similarity with the group [11] and the expertise of the group [44]. Future studies should analyze whether having robots with increased similarity to humans or with higher appearance of capabilities will also lead to more informational conformity.

Factors that increase normative conformity are group size, the immediacy of the group, and their social importance [30]. Future studies could analyze how changing the perceived social importance of the group, changing the number of robots, and changing how close the robots are will influence the frequency of normative conformity. Another factor that influences normative conformity is whether the other members are considered in-group or out-group [1]. Several studies have shown that in-group robots are rated more anthropomorphic and are favored over out-group members [1819]. Therefore it should be studied how group membership and anthropomorphism influence conformity.

Our results indicate that conformity is directly linked with the type of task being tested. Future work could analyze how conformity changes depending on the type of task and to further investigate if conformity to robots can be used in pro-social ways [14]. Last, conformity is influenced by individual characteristics [40]. Culture [6], age [15], gender [617], and other personal factors have been shown to influence the decision to conform in human groups. More studies on different personal factors should be studied to see how they influence conformity to robot groups.