Wednesday, January 26, 2022

The relationship between infidelity risk and oral sex: An independent replication of Pham and Shackelford (2013) and Pham et al. (2013)

The relationship between infidelity risk and oral sex: An independent replication of Pham and Shackelford (2013) and Pham et al. (2013). Rebecca B. Koessler et al. Personality and Individual Differences, Volume 189, April 2022, 111496.


• Oral sex has been suggested to be an adaptation to detect unfaithful partners.

• Oral sex has been shown to be related to partner infidelity risk for men, not women.

• Only null results regarding this association were replicated for women.

• A statistical error was identified in the original article.

• Support for this proposed evolutionary explanation of oral sexual behavior is mixed.

Abstract: In two studies, Pham and Shackelford (2013) and Pham et al. (2013) analyzed the relations between oral sexual behavior and partner infidelity risk in heterosexual couples. They found that indicators of partners' risk of infidelity were significantly associated with men's, but not women's interest in, and time spent performing oral sex after controlling for relationship length, relationship satisfaction and duration of sexual intercourse. We conducted a preregistered close replication of the methods and analyses of these studies using two distinct samples. In both samples, partner infidelity risk was not significantly associated with greater interest in and duration of oral sex for men or for women. The associations between infidelity risk and oral sexual behaviors were not significantly different between men and women, consistent with the original research. Exploratory analyses showed participants who suspected their partners of being unfaithful had significantly lower scores on the partner infidelity risk measure than those who did not hold those suspicions in Sample 1, while no significant difference emerged in Sample 2. These findings challenge the validity of the original partner infidelity risk measure. Overall, the current study offers contradictory evidence for the proposed evolutionary explanation for the adaption of oral sexual behaviors in humans.

Keywords: Infidelity riskOral sexReplication

Through improving the contractual structure, the China Fortune Land Development Co. model has been approved to be a more efficient way than traditional PPPs to promote large-scale comprehensive developments by reducing transaction costs

Rising private city operators in contemporary China: A study of the CFLD model. Yongli Jiao, Yang Yu. Cities, Volume 101, June 2020, 102696.


• Through improving the contractual structure, the CFLD model has been approved to be a more efficient way than traditional PPPs to promote large-scale comprehensive developments by reducing transaction costs.

• We can reconsider and reexplain the urbanization process in China from the perspective of transaction cost economics.

• China’s market reform is characterized by the dual-track structure in which the state-led and grassroots reforms co-exist. And we summarize the interactive mechanism of the state-led and grassroots reforms as “ex ante hands-off, ex post endorsement”.

• The emergence of the CFLD model means that China’s market reform has reached the core of planned economic system and market forces have extended from private goods to public goods.

Abstract: In the past decade, with the rise of private investment in urban development in China, there has been a profound transformation from government-led to market-led urban growth. These changes have created a boom in private city operators who have become involved in large-scale urban development and established long-term close public-private partnerships with local governments, integrating and optimizing all of the resources in a city or region. In this new business environment, China Fortune Land Development Co., Ltd. (CFLD) has undoubtedly been the earliest and most successful private city operator. This study uses the framework of transaction costs to analyze the CFLD model in detail, using the case of Gu'An New Industry City. We illustrate how it has reduced the principal-principal problem, the firm hold-up problem, and the government-led hold-up problem, the three types of transaction costs inherent in public-private partnerships, by improving the contractual structure. We believe it will become a far-reaching institutional innovation as an alternative to the land finance system to promote urbanization in contemporary China and beyond.

Keywords: Private city operatorTransaction costsContractual structurePublic-private partnershipsThe CFLD modelGu'An New Industry City

Social Status Predicts Different Mating and Reproductive Outcomes for Men and Women in China: Evidence from the 2010-2017 CGSS Data

Social Status Predicts Different Mating and Reproductive Outcomes for Men and Women in China: Evidence from the 2010-2017 CGSS Data. Yikang Zhang, Pekka Santtila. Research Square Pre-Prints, Jan 18 2022.

Abstract: Evolutionary psychological theories posit that higher social status is conducive to men’s reproductive success. Extant research from historical records, small scale societies, as well as industrialized societies, support this hypothesis. However, the relationship between status difference between spouses and reproductive outcomes has been investigated less. Moreover, even fewer studies have directly compared the effect of status and status difference between spouses on reproductive outcomes in men and women. Using data from the Chinese General Social Survey (CGSS) conducted between 2010 and 2017 (N = 55,875; 28,931 women) and operationalizing social status as standardized income and educational level (compared with same-sex peers), we examined how social status and relative status between spouses impact men’s and women’s mating and reproductive outcomes. We found that (1) men with higher social status were more likely to have long-term mating (being in a marriage and/or not going through marriage disruption) and reproductive success, mainly through having a lower risk of childlessness; (2) women with higher social status were less likely to have mating and reproductive success; and (3) relative status between spouses had an impact on the couple’s reproductive success so that couples, where the husband had higher status compared to the wife, had higher reproductive success. Thus, social status positively impacted men’s reproductive success, but relative status between spouses also affected mating and impacted childbearing decisions. 

Keywords: Social status, Mating success, Reproductive Success, Fertility


We utilized the 2010-2017 CGSS data to examine how social status is associated with Chinese men and women's mating and reproductive outcomes. In our analyses, due to the rapid expansion of education over the last few decades in China, we used statistical operations to separate the effect of standardized educational level (among same-sex peers) and absolute educational attainment. The results suggest that social status measured by standardized education level and income still predict reproductive success in terms of marital status and whether there are offspring in contemporary China. Furthermore, relative social status between spouses predicted the likelihood of having children and age at marriage among first-time married couples.

Effects of Social Status on Mating and Reproductive Outcomes

After isolating the effect of absolute educational attainment, men with a higher social status than their peers in terms of standardised education and income were more likely to be in a long-term relationship and stay in it. This result is consistent with the evolutionary hypothesis that higher social status is conducive to men’s mating success. In contrast, for women, social status had the opposite effect. However, the results do not warrant the conclusion that higher social status women have lower long-term mate value in the eyes of men. Although educated women have been perceived as less desirable, especially in cultures holding traditional gender roles (Bertrand, Cortes, Olivetti, and Pan 2020, Hwang 2016), this decreased desirability may reflect the status concerns of men rather than the low mate value of high- social status women.

Furthermore, past research has suggested that women exhibit greater hypergamy than men (Van Den Berghe 1960). Therefore, women with higher income may tend to choose from men who earn more than they do, and as a result, they face a much smaller mating pool, increasing the difficulty of finding a suitable long-term mate. On the other hand, men may also prefer women who have equal or lower social status compared with themselves, which has been a successful reproductive strategy in the past (Bereczkei and Csanaky 1996). The penalty educated women face in the mating market (Bertrand, Cortes, Olivetti, and Pan 2020, Hwang 2016) may result from social status concerns men may have (i.e., men may prefer to have partners who have relatively lower social status).

As for reproductive outcomes, a higher standardised income and education level were associated with more children for men. However, closer examination revealed that standardised education and income were only significant in predicting the first child for men. For women, a higher social status was associated with a decreased likelihood of having children. Combined with previous studies showing that the social status-fertility relationship is primarily driven by the high risk of childlessness among lower social status men (Kolk and Barclay 2021), the current results suggest that social status, in terms of income and standardized education level, positively contribute to men’s but not women’s reproduction. This is done through mating success and a better chance at transitioning to parenthood instead of having more offspring in an industrialized societal setting. Moreover, the current results are consistent with previous studies in Western populations (Hopcroft 2006, Fieder and Huber 2007, Hopcroft 2021), suggesting that Chinese data are an appropriate and integral part of evolutionary demographic research. However, it is also important to note that fertility is a complex issue that is not only influenced by an individual's social status but also societal changes (Newson et al., 2007), culture (McQuillan 2004), social welfare (Mills et al. 2011), and family planning policies (Liu and Liu 2020). Specifically, the way in which social status is associated with fertility change depending on regional or national social policies. For example, in more recent cohorts in Nordic countries, the negative relationship between women's educational level and fertility is diminishing due to social welfare reforms (Jalovaara et al., 2019).

Relative Status between Spouses for Predicting Mating and Reproductive Outcomes

Men who married relatively lower-social status women entered their marriages earlier and married a younger wife compared with those who married relatively high-social status women. This result is consistent with our hypothesis that men may make a trade-off between their partners’ social status (relative to themselves) and availability, as well as fecundity. However, as women do not necessarily prefer younger men as mates, we did not hypothesize a relationship between women’s status relative to their partner and their partner’s age. From Figure 1, it is clear that women with a higher social status than their spouses married later and had older spouses. However, after controlling for their own age, we did find a weaker but significant negative effect of educational difference on the partner’s age for women. Therefore, though women with relatively higher social status compared with their spouses had older spouses, this pattern is mainly driven by the fact that higher social status women enter marriage at an older age.

For reproductive outcomes, men who had higher relative social status than their spouses were more likely to have children. On the other hand, women were less likely to have children if their relative social status was higher. Notably, this pattern was significant after controlling for the couple's household income and average educational level, suggesting that relative social status in terms of resource potential may impact women’s childbearing decisions. In Figure 1, it is easy to see that besides hypergamy, homogamy is also associated with higher reproductive success. This is consistent with previous research, suggesting that both hypergamy and homogamy are successful strategies (Bereczkei and Csanaky 1996). The current results indicate that the relative social status difference between partners is more useful in predicting reproductive outcomes.

One may be concerned that the observed relationship could be explained solely by women, not men, being more likely to stop their education after having their first child and, thus, having a lower education level than their husbands. Another mechanism for this phenomenon, that does not require an evolutionary strategic explanation, would be personality differences. That is, women with stronger career motivations may devote more energy to advancing their social status and are, thus, less likely to have children. Both hypotheses would receive additional support if the observed phenomenon were present only in cases with a higher educational background. However, using only cases where education was no higher than high school or its equivalent (i.e., a subset where childbirth conflicts less with pursuing an education and a career), we replicated the findings that if the male partner has a relatively higher social status, the couple will have higher fertility (see Table S6 in supplementary materials). As for evolutionary explanations, whether the relationship is because women are more likely to bear children if their partner has a relatively higher social status or because women’s relative social status versus their partner’s is simply a more accurate way to measure social status within a subpopulation, demands further research. If the former is true, investigating whether this pattern is driven by a worse relationship associated with hypogamy (Kaukinen 2004) could also be a research topic of both theoretical and practical value. It could inform policymaking that may ameliorate the fertility decline, such as promoting a culture where social status is less determined by personal income and education and more associated with aspects of familial and social life.

Limitations and Future Directions

Though the CGSS data provided us with a large representative sample with several mating and reproductive success measures, it has several limitations. First, in measuring reproductive success, most of the surveys in CGSS did not differentiate between biological versus non-biological children, nor did the measurements exclude children who were deceased before reaching the age of reproduction. Second, the surveys were not linked with official records. Thus, the data could suffer from inaccurate self-reporting, especially for men’s reproductive success (Hopcroft 2021), which is also supported by the current analysis that, on average, women (M = 1.57, SD = 1.06) had significantly more children than men (M = 1.43, SD = 1.04), (1, 55653) = 256.6, p <.001. Third, income from the previous year is not an accurate measure of social status compared with wealth. This might explain the fact that standardized education was a slightly better predictor in our models. Finally, the analyses only provide correlational, but not causal, evidence due to its cross-sectional design. These limitations should be noted when making inferences.

As for the analyses, to make the current research more focused and concise, we controlled regional and ecological differences with random intercepts for rural and urban areas for each provincial region. However, it is well acknowledged that in China, rural-urban dualism (Zhang, Sun, and Liu 2021) and ecological features such as agricultural style (Talhelm and English 2020) impact behavioural patterns. Therefore, how these differences are reflected in reproductive decisions and outcomes should be conceptualized and examined.

Regarding the interpretations of the findings, especially for the sex differences found in our research, we should consider the cultural and demographical differences between China and other regions. For example, the sex ratio bias in China could also be a causal factor for the above results. Because the sex ratio is biased toward men, women would, in theory, have more bargaining power in the mating market, biasing both sexes toward high investment. The potential influence of the family planning policy should also be taken into consideration. The fact that social status only positively predicted the likelihood of having the first child for men could result from the former one-child policy in China rather than reflect an inherent feature of the social status-reproduction relationship.

Studying the relationship between social status and reproductive success is only part of the picture. Thus, researchers should also integrate findings from other areas of evolutionary science — for example, the study of personality and individual differences conferring social status (Durkee, Lukaszewski and Buss 2020), and behavioural genetics that links traits and genes (for a recent review, see Harden 2021). Specifically, recent research examining how the education-reproduction link could influence human population genetics found that because of the negative relationship between education and reproduction, selection has favoured genetic variants associated with low educational attainments (Beauchamp 2016; Kong et al. 2017). Future research could extend our understanding by investigating the relationships between social status-conferring traits (phenotypes), genetics, and educational and financial achievements together and contextualizing the observed patterns by incorporating cultural and ecological factors.