Sexual relationships

• Sexual Selection

  Sexual selection is a special case of natural selection.
• Intersexual selection

  • Sexual selection is where members of one biological sex choose mates of the other sex for reproduction. 
  • This is known as intersexual selection.
• Intrasexual selection

  • It can also refer to members of the same sex competing for access to members of the opposite sex.
  • This is known intrasexual selection.
• Reproductive advantage

  • Sexual selection explains why some characteristics often seem disadvantageous but actually give a reproductive advantage.
• Anisogamy

  Anisogamy refers to the differences between male and female sex cells (or gametes).
• Gametes

  • Gametes are very obvious in humans and non-human animals but differ significantly between male and females. 
  • Male gametes (sperm) are extremely small and highly mobile.
  • Sperm is created continuously in vast numbers from puberty to old-age. Males don't have to expend a lot of energy to produce sperm.
  • Female gametes (eggs or ova) are relatively large and static.
  • Ova are produced at intervals for a limited number of fertile years. 
  • Women use lots of energy producing ova.
• Consequences of Anisogamy

  • Anisogamy has many effects on mate selection, such as an abundance of fertile males but a much a smaller number of fertile females.
  • Anisogamy is also important in partner preference because it results in two different mating strategies, which in turn means there are two types of sexual selection: intersexual and intrasexual selection.
• Inter and intrasexual selection

  • Intersexual selection is the selection between the sexes, i.e. the strategies that males use to select females and females use to select males.
  • Intrasexual selection is competition within each sex, i.e. strategies between males to be the one that is selected.
• Buss (1989) - Sex Differences

  Buss (1989) studied the sex differences in mate strategies.
• Men prefer physically attractive women because they are healthier and therefore better mothers who will raise healthy children. They also tend to be younger so can bear more children.
• Evolutionary psychology suggests that these preferences reflect adaptations that evolved over time due to natural selection.
• Study explanation

  • Buss (1989) surveyed over 10,000 adults in 33 countries.
  • He asked them questions relating to age and a variety of attributes that evolutionary theory predicts should be important in partner preference.
• Study findings

  • Buss (1989) found that females placed a greater value on resource related characteristics, such as favourable financial prospects, ambition and industriousness.
  • Males valued reproductive capacity, such as good looks and chastity, and preferred younger mates more than females did.
• Study conclusions

  • These findings reflect sex differences in mate strategies. 
  • This is partly because of anisogamy.
  • The findings support predictions about partner preference derived from sexual selection theory. 
  • They can be applied across different cultures because they reflect fundamental human preferences not primarily dependent upon cultural influences.
• Attraction is influenced by physical appearance, personality, status and resources
• Changing partner preferences

  • Over the past century, partner preferences have changed.
  • Changes to social norms and sexual behaviours, which develop much faster than evolutionary timescales imply, have influenced partner preferences. ~These kinds of changes have come about through cultural factors, such as the availability of contraception.
  • Females are also more highly represented in the workplace and are no longer dependent on men to provide for them.
• Chang et al. (2011)

  • Chang et al. (2011) compared partner preferences in China over 25 years and found that some have changed but others remain the same. The changes corresponded with huge social changes.
  • So mate preferences are the outcome of a combination of evolutionary and cultural influences. Any theory that fails to account for both is a limited explanation.
• Evolutionary Theory

  Evolutionary theory makes predictions about partner preferences that are testable.
• • Clark and Hatfield (1989) sent male and female psychology students to a university campus. 
  • They were told to approach students and say to them: ‘I have been noticing you around campus. I find you to be very attractive. Would you go to bed with me tonight?’
• Clark and Hatfield (1980) findings 

  • No female students agreed to the request.
  • 75% of males agreed immediately.
  • This supports evolutionary theory.
  • This is because the study found that females are pickier than males when it comes to selecting sexual partners.
  • This implies that males have evolved different strategy to females to make sure they have reproductive success.
• Singh (1993, 2002)

  • Evolutionary theory predicts that males have a preference for female body shapes that indicate fertility. 
  • Singh (1993, 2002) wanted to test this by studying the role of female waist-hip ratios in influencing male preference.
• Singh (1993, 2002) findings

  • He reported that male preference is dependent on the ratio of waist to hip measurements, rather than overall female body size. 
  • Males generally found any hip and waist sizes attractive so long as the ratio of one to the other was about 0.7.
• Singh (1993, 2002) conclusions

  • The combination of wider hips and narrow waist is attractive because it is an ‘honest signal’ (it is hard to fake) that the woman is fertile but not currently pregnant.
• Waynforth and Dunbar (1995)

  • Waynforth and Dunbar (1995) studied lonely hearts advertisements in American newspapers.
  • They discovered that women were more likely to offer physical attractiveness while men offered resources and focussed on attributes such as success and ambition.
• Factors Affecting Attraction: Self-Disclosure

  Self-disclosure refers to the details people reveal about themselves to a partner. As breadth and depth increase, romantic partners become more committed to each other.
• Explanation of self-disclosure

  • People often don’t disclose too much about themselves early on in a new relationship.
  • But sharing things about ourselves helps people know each other better and helps to strengthen relationships.
• Altman and Taylor (1973)

  • Self-disclosure is a major concept within Altman and Taylor’s (1973) social penetration theory (SPT).
  • They studied the development of interpersonal relationships and the gradual process of revealing our inner-self to another person.
  • They argued that trust between two intimate partners is created through the reciprocal exchange of information.
  • By increasing these disclosures, romantic partners penetrate more deeply into each other’s lives. In the process, they gain a greater understanding of each other.
• Elements of Self-Disclosure: Depth and Breadth

  According to Altman and Taylor (1973), self-disclosure has two elements: breadth and depth.
• Depth

  • The metaphor of a multi-layered onion is often used to illustrate the idea of depth in self-disclosure. 
  • We disclose a lot about ourselves at the start of a relationship, but details are superficial (only on the surface, like the outer layer of an onion).
  • These are the kinds of details we might disclose to friends or co-workers.
  • Only as the relationship matures do we begin to disclose deeper details about ourselves.
• Breadth

  • Self-disclosure can be restricted because we see many topics as being off limits in the early stages of a relationship.
  • People don’t want to reveal too much too soon for fear of ruining the relationship.
  • This means their breadth of topics is reduced in the early stages of a relationship.
• “As intimacy increases so does the amount of personal information exchanged.”
• Elements of Self-Disclosure: Self-Reciprocity

  Another key element of self-disclosure is reciprocity. That is, once you have disclosed something to your partner, they will disclose something to you.
• Reis and Shaver (1988)

  • Reis and Shaver (1988) view reciprocity as essential for any romantic relationship to develop.
  • As we reveal something about our true self, our partner will respond. This increases levels of understanding, empathy and other intimate thoughts and feelings. 
  • This will also increase intimacy and deepen the relationship.
• Supporting Research for Self-Disclosure

  Research supports predictions about self-disclosure derived from social penetration theory.
• Sprecher and Hendrick (2004)

  • Sprecher and Hendrick (2004) studied heterosexual dating couples. 
  • They found a strong correlation between numerous measures of satisfaction and disclosure.
  • Men and women who used self-disclosure, and those who believed their partner did also, were more satisfied with and committed to their romantic relationships.
• Value of learning self-disclosure

  • If those who tend to limit communication to small talk can learn to use self-disclosure, then this can bring several benefits to their relationships in terms of deepening satisfaction and commitment.
  • These kinds of real-life applications show the value of these psychological theories.
• Cultural differences

  • Self-disclosure theory is a limited explanation of romantic relationships.
  • It is based on findings from Western (individualistic) cultures which are not necessarily generalisable to other cultures.
  • Additionally, the view that increasing the breadth and depth of self-disclosure leads to more satisfying intimate relationships might not be the case for all cultures.
• Correlational research

  • A lot of self-disclosure research is correlational.
  • So although it is usually assumed that greater self-disclosure creates more satisfaction, correlation tells us little about causal direction (i.e. what was the cause and what was the effect).
• Relationship Breakdown and Self-Disclosure 

  Relationship breakdown is characterised by a reduction in self-disclosure.
• Relationship breakdown

  • Relationship breakdown is characterised by a reduction in self-disclosure.
  • Using the onion metaphor, couples wrap themselves up once more in layers of concealment.