Parent-Offspring Conflict over Short-Term Mating Strategies

Individuals engage in short-term mating strategies that enable them to obtain fitness benefits from casual relationships. These benefits, however, count for less and cost more to their parents. On this basis three hypotheses are tested. First, parents and offspring are likely to disagree over short-term mating strategies, with the former considering these as less acceptable than the latter. Second, parents are more likely to disapprove of the short-term mating strategies of their daughters than of their sons. Finally, mothers and fathers are expected to agree on how much they disagree over the short-term mating strategies of their children. Evidence from a sample of 148 Greek-Cypriot families (140 mothers, 105 fathers, 119 daughters, 77 sons) provides support for the first two hypotheses and partial support for the third hypothesis. The implications of these findings for understanding family dynamics are further discussed.

Mate-seekers receive fitness benefits from using long-term strategies that enable them to attract and retain long-term partners.Fitness benefits are also derived from using short-term mating strategies that enable mate-seekers to find partners for casual mating (Buss & Schmitt, 1993).However, the choice of a partner does not depend entirely on the strategic choices of a mate-seeker as the mating game involves not only male and female offspring but also their parents (Apostolou, 2007b).
More specifically, in the great majority of contemporary pre-industrial societies parents exercise considerable influence in controlling the mate choice of their children, with arranged marriage being the most common pattern of mating (Apostolou, 2007b(Apostolou, , 2010;;Broude & Greene, 1983).In post-industrial societies, parents exercise indirect influence over the mating decisions of their children through means such as persuasion, threats, and appeals to loyalty (Perilloux, Fleischman, & Buss, 2008;Sussman, 1953).
So, parents engage also in strategic mating which aims to attract and retain mates for their children.In turn, this raises the question of whether the strategic choices of 1 Correspondence concerning this article should be addressed to Dr. Menelaos Apostolou, Department of Social Sciences, University of Nicosia, 46 Makedonitissas Ave., 1700 Nicosia, Cyprus.Email: m.apostolou@gmail.com;apostolou.m@unic.ac.cy.children comply with those of their parents or if the two parties are in conflict over mating strategies.
A recent body of research indicates that parents and offspring disagree over long-term mating strategies as the ideal spouse for children is not the ideal in-law for their parents.In particular, traits such as beauty and exciting personality are preferred more in a spouse than in an in-law (Apostolou, 2008a;Buunk, Park & Dubbs, 2008;Dubbs & Buunk, 2010;Perilloux, Fleischman, & Buss, 2011), whereas traits such as good family background and similar religious background are preferred more in an inlaw than in a spouse (Apostolou, 2008b;Buunk et al., 2008;Dubbs & Buunk, 2010;Perilloux et al., 2011).
Parents have primarily long-term strategies; that is, they are mainly interested in finding long-term mates for their children (Apostolou, 2009).Accordingly, the question that arises is whether the short-term mating strategies of children conflict with the longterm mating strategies of their parents.Presently, there is only one study that has attempted to provide an answer: Apostolou (2009) asked British parents to rate how acceptable they considered a set of short-term mating strategies to be for themselves and for their children.Participants rated the majority of these strategies as more unacceptable for their children than for themselves, indicating a possible disagreement between parents and offspring.The present study aims to identify whether there is indeed disagreement over short-term mating strategies by examining both parents and their children.

Parent-offspring conflict over mating strategies
One strategic option for a man is to find a partner, stay with her, have children with her and divert his resources to these children.The substantial cost involved in this strategy is balanced by the fitness benefit coming from the increased probability of having offspring who reach sexual maturity (Buss, 2003;Buss & Schmitt, 1993).On the other hand, a brief sexual encounter has a small chance of producing a child that survives to sexual maturity; however, the cumulative probability of many such relationships is much higher, making short-term mating another strategic option for a man to increase his fitness (Buss, 2003;Buss & Schmitt, 1993).
Having many casual relationships does not increase the fitness of a woman in terms of having more offspring.Still, a woman can receive fitness benefits by engaging in short-term mating.To begin with, she can exchange sex for resources that she can divert to her children.Also, a woman can establish relationships with men who can become long-term mates or who could support her in case her husband leaves her or he does not come back from hunting or war.Furthermore, men will not make long-term commitments with women of a mating value less than their own, but they are willing to have casual sex with women of lower mating quality; thus, a woman can marry a man of similar quality to herself and seek better genes for her children in casual relationships outside marriage (Buss & Schmitt, 1993).Furthermore, when parental choice is dominant, which is usually the case in most human societies (Apostolou, 2007a(Apostolou, , 2010)), offspring have to subject their mate choices to the approval of their parents.As in-law and mate preferences diverge (see above), the choices of parents are not going to satisfy the preferences of their children, a likely scenario being that the latter will find themselves married to individuals who are not as beautiful as they would like and they could obtain if they themselves were exercising mate choice.Individuals can therefore balance this loss in genetic quality by seeking good-looking individuals outside marriage.In effect, then, short-term mating strategies are also a way for both men and women to bypass parental choice (Apostolou, 2009).This is an obvious reason why parents are likely to disagree with the short-term mating strategies of their children, but it is not the only one.To begin with, adultery is a primary reason for divorce (Betzig, 1989), so an extramarital relationship can jeopardize a marriage that parents have arranged.Moreover, if a casual relationship evolves into a long-term one, this can also be damaging for parents, as a mate's traits will reflect their offspring's preferences and not their own.
Offspring engage in short-term mating because this increases their fitness, which means that it also increases the fitness of their parents as the two are genetically related.
One primary benefit of short-term mating comes from being able to access good genes (Buss & Schmitt, 1993).This benefit, however, counts less for parents than for their children.This is because the coefficient of relatedness of parents to children is 0.5, but the coefficient of relatedness of grandparents to grandchildren is only 0.25.This translates into a spouse of superior genetic quality increasing the chances that 50% of an individual's genes will pass successfully to the next generation, but an in-law of superior genetic quality increases the chances that only 25% of an individual's genes will pass successfully to the next generation.Therefore, individuals reap more genetic benefits from a casual mate of good genetic quality than their parents do.
Overall, as offspring's short-term mating is less costly and more beneficial to them than to their parents, it is predicted that the two parties will disagree over shortterm mating strategies, with offspring considering these as more acceptable than their parents do.

Daughters vs. Sons and Mothers vs. Fathers
Females, by investing more in their offspring, become a scarce reproductive resource to which males seek access (Trivers, 1972).So, by controlling their female offspring, parents can extract valuable resources from males and their families.
Accordingly, there are more fitness benefits for parents controlling the mating behavior of their daughters than that of their sons (Apostolou, 2007b).In turn, this means that parents should be more anxious about losing control of the mating behavior of their daughters than that of their sons.
Moreover, a short-term relationship may result in committing a daughter's parental investment (i.e., pregnancy) to a man whom her parents do not approve (Perilloux et al., 2008).Also, owing to parental uncertainty, males place a premium on the chastity of the female (Buss, 2003), which means that the latter's short-term mating is likely to have a bigger impact on the status of her family than the former's short-term mating.Finally, if a casual relationship ends in pregnancy, it is usually the father who walks away, so the burden of childrearing falls on the mother and her parents.
Consequently, maternal grandparents have to shoulder a higher burden in terms of supporting their grandchild to compensate for the loss of the father; a cost that parental grandparents may not suffer (Apostolou, 2009).For these reasons, parents are expected to consider short-term mating more unacceptable when it involves a daughter than when it involves a son.
Finally, the costs of offspring's short-term mating strategies fall equally on the shoulders of mothers and fathers.For instance, a casual relationship compromises both parents' ability to arrange a desirable marriage.Accordingly, mothers and fathers are expected to be in agreement on how much they disapprove of the short-term mating strategies of their children.

Participants
Two research assistants were employed for the purposes of this study.They recruited families who volunteered to participate in research on family conflict (no payment was given).To qualify for participation, a family had to have at least one child who was over thirteen years of age.The research assistants were given instructions to recruit participants from diverse socioeconomic backgrounds.They visited families in their homes and administered the survey to each family member who was willing to participate.Participants completed the questionnaire independently, and upon completion they put the questionnaire in an unmarked enveloped and sealed it.
With respect to mothers, 84.3% of were married, 10% were divorced, 4.3% were widowed, .7%were single and .7%were in a relationship.Moreover, 94.3% of fathers were married, 2.9% were divorced, 1.9% were in a relationship and 1% were widowed.
With respect to daughters, 55.1% were single, 25.4% were married and 19.5% in a relationship.Finally, 53.9% of sons were single, 22.4% were married, 17.1% were in a relationship, and 6.6% were divorced.

Materials
The survey came in two versions, one administered to parents and the other to their children.The version administered to parents had three parts.In the first part, demographic information was collected (sex, age, marital status, number of daughters and sons, age of the oldest male child and the oldest female child).In the second part, participants were asked to rate how acceptable they considered a set of short-term mating strategies for their daughters and for their sons assuming that both of them were single.In the third part, participants were asked to rate how acceptable they considered a set of short-term mating strategies assuming that their offspring were married.The order of presentation (daughter-son, single-married) was balanced across participants.
The version administered to children had a similar format: In the first part demographic information was collected.In the second part, participants were asked to rate how acceptable they considered a set of short-term mating strategies for themselves assuming that they were single and in the third part to rate a set of short-term mating strategies assuming that they were married.The order of presentation (single-married) was balance across participants.A seven-point Likert scale was used to measure acceptability (1-not at all acceptable, 5-moderately acceptable, 7-very acceptable).
The instrument employed to measure short-term mating strategies is an expanded version of that developed by Apostolou (2009).A frequently used strategy that was not captured by the earlier version of this instrument is payment in order to gain sexual access.Thus, in the version employed here we have amended the 'pay someone to have sex with me/daughter/son' item so as to have a more inclusive shortterm mating strategies instrument.

Parents vs. Offspring
A P-P plots analysis indicated several instances of violation of the normality assumption.Accordingly, in order to identify differences a series of Wilcoxon's signedrank tests was applied to the acceptability ratings of parents and their offspring.The comparative results for mothers vs. daughters and mothers vs. sons are presented in With respect to mothers vs. daughters, the first thing we can see is that both parties consider short-term mating to be generally unacceptable, with their mean ratings being less than two.Nevertheless, in almost all comparisons daughters consider shortterm mating strategies significantly more acceptable for themselves than mothers consider them for their daughters.In Table 2 we can see the results of comparisons between the ratings that mothers gave for married daughters vs. married daughters.In most cases daughters consider short-term mating to be slightly more acceptable than their mothers but none of the differences passes the significance level.
In mothers vs. sons comparisons we see that mothers consider short-term mating to be significantly less acceptable than their sons consider it for themselves (Table 1).
When we move to married sons we notice a substantial reduction in the acceptability ratings for both mothers and sons (Table 2).Nevertheless, mothers still consider shortterm mating for their married sons to be significantly less acceptable than their married sons consider it for themselves.Finally, when we move from mothers vs. daughters to mothers vs. sons we find more comparisons that are significant and have greater effect sizes.sons.For fathers vs. daughters we see that both parties consider short-term mating to be unacceptable, but fathers consider it to be more unacceptable for their daughters than their daughters consider it to be for themselves.With respect to the 'pay someone to have sex with' item, all fathers considered it to be very unacceptable for their daughters.
In Table 4 we see comparisons between the rating that fathers gave for married daughters and the ratings of married daughters.Only one difference is significant, indicating less disagreement between fathers and married daughters than between fathers and single daughters.
With respect to fathers vs. sons, we can see that both parties consider short-term mating to be moderately acceptable (Table 3).Fathers, however, consider short-term mating to be significantly less acceptable for their sons than their sons consider it for themselves.Comparisons between the ratings that fathers gave for their married sons and married sons gave for themselves indicate that both parties consider short-term mating unacceptable; however, fathers consider it more unacceptable for their sons than their sons consider it for themselves.Finally, when we move from fathers vs. daughters to fathers vs. sons we find more comparisons to be significant and have greater effect sizes.

Daughters vs. Sons and Mothers vs. Fathers
A series of Wilcoxon's signed-rank tests was applied to the ratings that parents gave for their daughters and the ratings that they gave for their sons.The results indicate that mothers considered the short-term mating of their daughters to be significantly less acceptable than the short-term mating of their sons (Table 5).This is also the case for married daughters vs. married sons (Table 6).Similarly, fathers considered the shortterm mating of their daughters to be significantly less acceptable than the short-term mating of their sons (Table 5), and the short-term mating of their married daughters to be significantly less acceptable than the short-term mating of their married sons (Table 6).Cohen's d indicates a large effect of the sex of the child on the ratings of the parents.children than by parents.Overall, then, marriage has an effect as it makes people more disapproving of short-term mating; however, this effect is stronger for offspring than for their parents.
Finally, we were interested to explore whether participants' age has an effect on how acceptable they consider short-term mating.The ratings for each item in the survey that parents gave for their children and children gave for themselves were regressed on each party's age.For the majority of cases, the age variable was significant with a negative coefficient, indicating that as people age they become less approving of shortterm mating.

Discussion
The results provide support for the hypothesis that parents and children disagree over short-term mating strategies, with the former considering these as less acceptable than the latter.It is also found that disagreement between the two parties is reduced when the children are married.Moreover, parents consider short-term mating strategies less acceptable for their daughters than for their sons.Finally, mothers and fathers agree with respect to how much they disagree over their daughters' short-term mating; however, this is not so with their sons, as fathers are less disapproving than mothers.
The latter result is not consistent with the hypothesis that parents are in agreement over the short-term mating of their children.Although this finding needs to be replicated, it indicates that the short-term mating of sons may be less costly to fathers than to mothers.Another possible explanation is that fathers, being themselves more prone to short-term mating strategies than their wives, empathize more with their sons than with their daughters, something that makes them more approving of the short-term mating behavior of the former.Regardless of the reason for this difference, we expect that fathers will be more permissive with regard to their sons than their wives would like, and this may be a cause of friction between the two.
Moreover, parents are more disapproving of the short-term mating strategies of their daughters than of their sons and thus they should be more disturbed if their daughters rather than their sons engage in short-term mating.Accordingly, we expect that there will be fights between parents and children over the latter's short-term mating behavior; however, the daughters-parents fights are expected to be more severe that the sons-parents ones, as parents consider their daughters' short-term mating to be a more serious breach of good conduct.
On this basis, we can predict further that parents will guard their daughters more closely in order to prevent them from engaging in short-term mating, and they will apply punishment if they are caught doing it.In turn, this indicates that female mate seekers will try to be secretive about their relationships so as to avoid unleashing the wrath of their parents.If asymmetrical punishment against daughters for engaging in short-term mating was a recurrent phenomenon during human evolutionary time, it might have resulted in daughters conforming more to their parents' preferences in order to reduce the cost of punishment.This could partly explain why there is less divergence in acceptability ratings between parents and daughters than between parents and sons.
Finally, we can predict that because people, as they age, become more disapproving of short-term mating strategies, there should be greater conflict in cases where there is a large age difference between parents and their children than where the age gap is small.Therefore, individuals who choose to have children later in life will find themselves disagreeing more often over mating with their offspring than parents who have children earlier on.
This is the first study that employs both parents and children to demonstrate disagreement over mating strategies between the two.Making comparisons between parents and their actual offspring has obvious strengths, but there are also limitations.
One such limitation is that the study design does not control for alternative explanations based on social learning or age effects.The hypothesis put forward here is that parents have evolved to disapprove of the short-term mating strategies of their children because this enhances their fitness in terms of better control over mate choice.The difference in approval of short-term mating strategies may also be owed, however, to the age effect: as people get older they become more conservative.Therefore, the difference in ratings can be explained by the age difference (older parents versus younger children).Still, the results of a study which employed a within-participants design (i.e., Apostolou, 2009) that controlled for age effects indicate the presence of evolved predisposition effects.
Thus, a more plausible scenario is that the age effects add to the evolved predisposition effects to produce the disagreement measured here.
Another limitation is that this study is based on self-report data which can potentially introduce a number of biases: for instance, mate-seekers may rate short-term mating as more unacceptable than they actually consider it to be.If this is so, the degree of parent-offspring conflict over short-term mating strategies may have been underestimated here.Finally, this study is limited to a single culture and future research should attempt to replicate its findings in different cultural contexts.
To conclude, parents do not always agree with the mating behavior of their children, an area of disagreement being the latter's short-term mating strategies.This disagreement has significant implications for family dynamics and interfamily conflict that future research should attempt to explore.

Table 2 .
Mothers vs. Married Daughters and Mothers vs. Married Sons Rating Differences Table 3 presents the comparative results of fathers vs. daughters and fathers vs.

Table 3 .
Father vs. Daughters and Fathers vs. Sons Rating Differences

Table 4 .
Fathers vs. Married Daughters and Fathers vs.

Table 5 .
Daughters vs. Sons Ratings Differences

Table 6 .
Married Daughters vs. Married Sons Ratings Differences