What They Mean to Us and What They Mean for Our Relationships Sexual Behaviors: What They Mean to Us and What They Mean for Our Relationships Jennifer A. Shukusky, The University of Texas at Austin Paul W. Eastwick, University of California - Davis IARR July 23, 2016

Here are some mammals. Upon reaching sexual maturity, each of these mammals goes into heat, otherwise known as “estrus”

Estrus: “The periodic state of sexual excitement in the female of most mammals that immediately precedes ovulation and during which the female is most receptive to mating” Estrus is “the periodic state of sexual excitement in the female of most mammals that immediately precedes ovulation and during which the female is most receptive to mating” Estrus is a term that our friends over in the bio dept use frequently, but not typically applied to humans.

1923: Estrogen discovered and named “the generator of estrus” Estrogen is a family of hormones, the most common of which is estradiol, which surges prior to ovulation.

For some mammals, that surge of estrogen results in an outward display of fertility. Depicted here, is the a female baboon with swollen anal glands. For some non-human primates, estrus is really obvious.

In women, however, ovulation is difficult to recognize. Does anyone want to guess in which photo this woman is at peak fertility? It’s the left. Additionally, unlike most other mammals who engage in sex only when they are likely to conceive, women are sexually receptive all cycle long.

Ovulation effects in women No change in sexual frequency The scent of symmetry Symmetry is associated with high genetic quality T-shirt smelling study Because we don’t see obvious physical sign of ovulation in women AND there is no change in sexual frequency throughout women’s menstrual cycle (save a slight dip during menses) Researchers started to think that women evolved beyond estrus. With further investigation, however, researchers HAVE detected some shifts in behavior during peak fertility, specifically, in terms of women’s mate preferences. Estrous (ovulating) females are particularly attracted to specific males. Most notably, during ovulation, women were found to prefer the scent of men with symmetrical body features (ear width, finger length, etc.) Why? Symmetry is a byproduct of high genetic quality. These ovulating women, by smelling the t-shirts of men who wore them for 2 straight days, indicated preference for the scents of the most symmetrical men. The preferences of non-fertile women, however, were sporadic. Ovulation effects in women

Expect women to stray during ovulation BUT, the pair-bond is adaptive: Investment/provisions from two parents Support each other in child rearing Raise a child to sexual maturity Based on the observed shift in mate preferences, strongly evolutionarily-minded folks may believe that women might stray from their primary partner during ovulation in pursuit of a mate of high genetic quality. Right? That would be adaptive. However, straying would risk losing a pair-bond with the primary partner, which is also adaptive. A monogamous relationship implies investment from two parents Having two parents creates a stable environment in which the child can develop and reach sexual maturity Evolutionary benefit?

Models of Ovulatory Adaptations in Partnered Women #1 Adaptive workarounds #2 Extended sexuality Pair-bond adaptations alter fertile phase sexual behavior Prediction: Highly bonded women in fertile phase will engage in relationship-strengthening behaviors Pair-bond adaptations alter non-fertile phase sexual behavior Prediction: Sexual behavior outside of the fertile window fosters investment and interest from the primary partner A brand new paper by our very own Paul Eastwick and others outlines a few integration models attempting to explain ovulatory adaptations in partnered women. The first model is that of Moderation by relationship features, or adaptive workarounds. According to this model, ovulation effects are directed towards one’s primary partner The second model is that of extended sexuality. According to this model, non-reproductive sexual behavior (occurring when not fertile) have a purpose- to elicit investment and interest from the primary partner Although both camps support the adaptation of the pair-bond, the manifestation of behavior in each case is different. To compare, #1 says that the increase in behavior will occur while fertile And #2 says that an increase in behavior will occur while NOT fertile. Models of Ovulatory Adaptations in Partnered Women Durante, Eastwick, Finkel, Gangestad, & Simpson, 2016

How does sexual engagement in specific behaviors fluctuate throughout the menstrual cycle? So let’s test it! We already know there is no change in sexual frequency throughout the cycle, but if sexual engagement has a PURPOSE, we might focus on which specific sexual behaviors are occurring throughout the cycle. Other research has shown that engagement in specific sexual behaviors varies in how we think about them, the partners with whom we choose to engage in them, and their specific functions in our relationships. Let me elaborate. Research Question

Specific sexual behaviors Janus & Janus, 1993: Anal intercourse is “kinkier” than other sex acts Shukusky & Gleason, in prep: Likelihood of engaging in specific acts depends on exclusivity and closeness with relationship partner Cognition/connotation: we think about specific behaviors differently. For example, anal intercourse is considered by most to be significantly “kinkier” than other sexual acts (Janus & Janus, 1993) 2. There is also evidence that people discriminate between the sexual behaviors in which they engage depending on the exclusivity and closeness of their relationship to their sexual partner (Shukusky, 2013). LET’S TAKE A LOOK!

Shukusky & Gleason, in prep People discriminate between relationship types with sexual engagement Therefore, sexual behaviors may have different connotations Shukusky & Gleason, in prep

Shukusky & Gleason, in prep People discriminate between relationship types with sexual engagement Therefore, sexual behaviors may have different connotations Shukusky & Gleason, in prep

Specific sexual behaviors Janus & Janus, 1993: Anal intercourse is “kinkier” than other sex acts Shukusky & Gleason, in prep: Likelihood of engaging in specific acts depends on exclusivity and closeness with relationship partner Sela et al., 2015: Benefit-provisioning strategy: People spend more time performing oral sex on their partner to increase relationship satisfaction 3. Some sexual behaviors may even serve specific functions in a relationship; for instance, oral sex functions as a mate retention behavior for men and women who have more interest in and spend more time performing oral sex on their partner (Sela, Shackelford, Pham, & Euler, 2015). This is benefit-provisioning strategy to increase their partner’s relationship satisfaction. An issue her: JUST an association (correlation) between the number of mate retention behaviors in which people engage (verbal and phys signs of possession, derogating competition) And the amount of time they spend and interest they have in performing oral sex on their partner. Nonetheless, serves as evidence that oral sex may be a way to help maintain our relationship- keeping our partner satisfied.

Romantic-ness Pair-bondedness: Highly correlated concepts Romance Commitment Investment Satisfaction Highly correlated concepts Romance More ecologically valid A proxy for pair-bonding characteristics The models I described to you earlier have a focus on pair-bondedness. We often talk about relationships in terms of commitment, investment, satisfaction, or relationship maintenance. In an exploration of specific sexual behaviors, It’s difficult to identify the most commitment-y behaviors As opposed to the most romantic behaviors. So, I’m using romance as a proxy to explore the kinds of highly correlated concepts we are trying to tap into - looking at how ROMANTIC people find each behavior to be - and how one’s engagement in these romantic sexual behaviors fluctuate throughout the cycle. Romantic-ness

Evaluations/connotations of sexual behaviors across the menstrual cycle Engagement in sexual behaviors across the menstrual cycle Some behaviors can be used to increase satisfaction One dimension on which these behaviors may be relevant to the strengthening of a pair bond Is how romantic they are. Current studies

Study 1: How people think about specific sexual behaviors Study 1 investigates how people view specific sexual behaviors (specifically, how romantic people think they are) and how these evaluations may fluctuate throughout the menstrual cycle. Study 1: How people think about specific sexual behaviors

Hypotheses Do people discriminate between specific sexual behaviors regarding the level of romance associated with each? Does fertility status predict women’s cognitions about these behaviors? 1. Do people discriminate between specific sexual behaviors regarding the level of romance associated with each (as determined by mean romantic scores)? 2. Looking only at the naturally-cycling women in the sample, does fertility status predict women’s cognitions about these behaviors?

Procedure Participants were recruited through Mturk Paid $0.45 to complete an online survey: Most recent sexual partner length of time known, relationship category Condom/drug/alcohol use Engagement in 35 sexual activities Evaluation of 35 sexual activities: romantic arousing appealing Demographics Women: cycle info during their most recent sexual encounter with that person. 35 sexual activities (including kissing, being stimulated with sex toys, sexual [vaginal] intercourse, etc.), participants indicated the acts in which they engaged during their most recent sexual encounte

Measures Level of romance Fertility status M = 5.35 (SD= .98) Ranged from 3.43 (receiving anal sex) to 6.78 (kissing) Fertility status Wilcox likelihood of pregnancy value (Wilcox, 1990) was assigned to the women’s cycle day These values range from .000 to .086 Level of romance. The level of romance of each activity was determined by taking the average of all participants’ romantic ratings for each act. Participants were able to indicate on a 1-7 Likert scale how romantic they found each act to be. The average mean was 5.35 (SD= .98), and means ranged from 3.43 (receiving anal sex) to 6.78 (kissing). Fertility status. The fertility status of the naturally cycling women in this sample was determined from the day of her cycle. Participants reported the date of their last period, which was used to calculate their cycle day when taking the survey. Then, a Wilcox likelihood of pregnancy value (Wilcox, 1990) was assigned to the women’s cycle day. These values range from .00 to .80. Measures

Participants 201 (83 men, 116 women, 2 “other”) completed the survey Age: 18 - 74 (M= 37.11, SD= 12.85) Predominantly (58.1%) white 31% were “not religious” and 12% were “very religious” 86.7% had college experience, 43.6% had a degree All heterosexual All sexually active Because the study is focused on heterosexual sexual acts, these individuals, and those who have not engaged in any sexual behavior, were excluded in the analyses. Participants

Results: Most Romantic 35 total behaviors were rated, most considered quite romantic 1 (Not romantic at all) to 7 (Extremely romantic) Activity Mean SD Kissing 6.78 1.66 Hugging/Cuddling 6.70 1.63 Talking lovingly about feelings for partner 6.64 1.83 Partner talking lovingly about his/her feelings 6.51 1.92 Holding hands 6.44 1.76 A romantic atmosphere 6.43 1.84 Gazing into eyes 6.42 Playing with hair 6.37 1.82 Sexual (vaginal) intercourse 6.36 2.03 Foreplay 6.34 1.89 Fondling her breasts 6.33 Being told how sexy you are 6.23 1.81

Results: Least Romantic 35 total behaviors were rated, most considered quite romantic 1 (Not romantic at all) to 7 (Extremely romantic) Activity Mean SD Being stim with sex toys 4.29 2.79 Stim partner with sex toys 4.26 2.77 Playing rough 4.17 Fantasizing 4.15 2.94 Watching erotica 4.07 3.02 Giving anal sex 3.72 Receiving anal sex 3.43 2.82

Results 49 naturally-cycling women with regular cycles A mean was calculated for all activities to determine the women’s overall romance ratings. 94 naturally-cycling women in the sample, 49 had regular cycles

Results F(1,47)=.491, p=ns. * N = 49 Adaptive workarounds Extended Sexuality A linear regression model, examining the ability of Wilcox values to predict romance level explained only 1.0% of the variance was not significant, F(1,47)=.491, p=ns.

Results .08 .06 Fertility status .04 .02 SAME DATA, now mapped on Day of Cycle Overall, fertility status (quantified by Wilcox’s likelihood of pregnancy values) did not predict women’s overall perceptions of romance.

The variation in evaluations of each behavior indicate that people discriminate between specific sexual acts regarding their level of romance. However, no relationship between fertility and romantic evaluation of sexual behaviors was found. Quick summary

Study 2: When people engage in specific sexual behaviors No changes across the cycle in how people think about specific sexual behaviors, but how might engagement in specific sexual behaviors change across the cycle? Study 2: When people engage in specific sexual behaviors

Hypotheses Does fertility predict the number of sexual behaviors in which women engage? (2) Does fertility predict the mean romance level of the sexual behaviors in which women engage? The following questions are addressed using these data:

All students enrolled in an introductory course on human development were eligible to participant in research studies for extra credit. Because this study required participants to meet specific criteria, all women in the course were contacted with a personalized email inviting them to indicate their eligibility and interest in participating in the “Relationship Activities” study. Eligible women were not taking hormonal birth control, experienced a “regular” menstrual cycle, and had sexual experience with a man. Procedure

Measures Romantic-ness Fertility status Romantic-ness. The romantic evaluation of the sexual behaviors in this study come from the ratings provided by the participants in Study 1. Fertility status. Fertility status was calculated using the same procedure described in Study 1. Measures

Participants 56 naturally cycling women Age: 18-22 (M= 19.30 years, SD=1.19) 1/3 White, ¼ Black, ¼ Hispanic 60% somewhat religious or very religious 54.3% in a committed, romantic relationship 1 not heterosexual (not included in analyses) Fifty-six naturally cycling women participated in Study 2. They ranged in age from 18 to 22 with a mean of 19.30 years (SD=1.19). They were predominantly (34.4%) white, though an additional 25.3% were black, 25.8% Hispanic, 7.2% Asian, and 7.3% other.). Of the sample, 18.1% identified as “not religious,” 21.7% were “a little religious,” 29.0% were “somewhat religious,” and 31.2% were, “very religious.” Additionally, 54.3% of the participants identified as being in a committed, romantic relationship. One participant strongly disagreed or disagreed with the statement, “I am exclusively attracted to members of the opposite sex.” Because the study is focused on heterosexual sexual acts, that individual was excluded in the analyses. Participants

Results Fertility status β = 14.57, t(75.55) = 0.82, p = .42 .08 .06 .04 .02 Fertility status The model revealed no significant relationship between the number of sexual acts and the participants’ fertility status. Ultimately, no evidence of ovulation effects were found on the number of behaviors in which the women participated. Fifty-five naturally-cycling, sexually active women were followed across 28 days; all but one (who provided only 3) provided all 4 weeks. β = 14.57, t(75.55) = 0.82, p = .42

Results Fertility status β = -1.08, t(78.20) = -1.26, p = .21 .08 .06 .04 .02 Fertility status Consequently, no evidence of ovulation effects were found on the mean romance level of behaviors in which the women participated. β = -1.08, t(78.20) = -1.26, p = .21

Summary of Results Overall: Fertility status had no effect on the participants’ engagement in a specific number of activities Fertility status had no effect on the participants’ engagement in romantic activities Overall, the results of the mixed models reveal that fertility status had no effect on the participants’ engagement in a specific number of activities, romantic activities.

Specific sexual behaviors were used to test potential ovulatory shifts in naturally-cycling, sexually active women. Broadly, little evidence of ovulatory shifts were found. In the current studies, evaluations of specific sexual behaviors were utilized to test potential ovulatory shifts in naturally-cycling, sexually-active women. Broadly, no evidence of ovulatory shifts were found in the current data when analyzing the number of sexual behaviors in which women engage and want to engage OR the romantic-ness of those behaviors. These data are more in line with the predictions of model 2, which posits that women’s extended sexually promotes sexual engagement across the cycle (and in non-fertile phases) as a mate-retention tactic (Durante et al., 2016). Sexual engagement can increase relationship satisfaction and therefore, increase investment in the relationship (e.g., Sela et al., 2015). General discussion

Models of Ovulatory Adaptations in Partnered Women #1 Adaptive workarounds #2 Extended sexuality Pair-bond adaptations alter fertile phase sexual behavior Prediction: Highly bonded women in fertile phase will engage in relationship-strengthening behaviors Pair-bond adaptations alter non-fertile phase sexual behavior Prediction: Sexual behavior outside of the fertile window fosters investment and interest from the primary partner Let’s return to our models: Models of Ovulatory Adaptations in Partnered Women

We found no support for ovulation effects Not everyone was in a committed relationship Potential moderators What’s going on here? There are some strong critiques that ovu effects are bs, however, ample evidence (including a noteworthy meta-analysis, and pre-registered studies) shows that that is NOT the case. For a study about pair bonds, not everyone is necessarily bonded to their partner People engage in all sorts of behaviors with not committed partners (you saw my graph from work with Marci) Can look at partners v. non- partners (each participant indicated their relationship to their sex partner each week) Can make comparisons across relationship types (relationship to sex partner) Can look at relationship status and attachment bond strength as moderators. Seemingly want to avoid pregnancy (18-22 yrs old and still enrolled in undergraduate courses) Sexually active, not taking hormonal birth control, half people in rels (using condoms?) shifts in behavior to avoid pregnancy when vulnerable We have condom use, so we can control for that Additionally, we have desired behaviors for those who were not sexually active on any given week. We also have photos of their partners. OVULATORY SHIFTS predict attraction to alternatives IF primary partner lacks positive qualities (genetic quality) General discussion

Address dispute between theorists on the evolutionary adaptations of menstrual cycle effects Provide insight into how sexual engagement maps on to existing integrative models of behavior The adaptive workarounds model was directly supported by the data, though we may have found support for the extended sexuality model By examining sexual engagement across the menstrual cycle, the effects of ovulatory shifts can be used to support predicative models of behavioral outcomes. Although no support for the adaptive workaround model was found, there may be some evidence that the extended sexuality model is supported, but only the surface has been scratched. Conclusion

Special thanks to the Eastwick lab for extensive feedback on an earlier version of this talk.