Relationships
Sexual Selection and Human Reproductive Behaviour:
Sexual selection and human reproductive behaviour
- Darwin’s (1871) theory of sexual selection says that
people select characteristics that aid reproduction Self-disclosure
rather than survival. Physical attractiveness
- Females look for signs of genetic fitness in a partner.
- Aggressiveness is adaptive as it gives males an Filter Theory
advantage over competitors for reproductive rights. Social Exchange theory
- Anisogamy is the difference between male and
Equity theory
female sex cells.
- Sperm cells are small, mobile, and continuously Rusbult’s investment model
produced from puberty to old age. Duck’s phase model
- Egg cells are large, static and all formed before birth.
There are only a limited number of fertile years and Virtual relationships in social media
require a significant investment of energy. Parasocial relationships
- The consequence of anisogamy is that there are
plenty of fertile males and fewer fertile females.
Inter-sexual selection:
- Inter-sexual selection is the selection of mates between sexes.
- Females make a greater investment of time and commitment before, during and after birth. Due to
this they need to be choosier than males, so they seek a male who will provide healthy offspring and
support them.
- The traits which are preferred by females are passed on. Height is a marker of genetic fitness in males,
so the females who choose the tallest males will have greater reproductive success and innate
preferences are passed on. This characteristic will then increase in future generations.
- Over time taller and taller men will be selected and this is called the runaway process.
Intra-sexual selection:
- Intra-sexual selection is the selection of mates within sexes.
- Males reproduce as frequently as possible and have to compete with each other for mates as there is a
shortage of fertile females.
- Males who are successful pass on their genes to the next generation.
- Aggression is one of these characteristics as the most aggressive males are more likely to reproduce
- Males also prefer youthful and fertile women because these are signs of fertility leading to reproductive
success.
AO3:
+ A strength of inter-sexual selection is evidence for female choosiness in heterosexual relationships.
Clark & Hatfield (1989) sent students to ask others ‘I have been noticing you around campus. I find you
to be very attractive. Would you go to bed with me tonight?’. None of the female agreed to this,
however 75% of the males did. This supports the view that females are choosier than males, and males
have a different strategy to ensure their reproductive success.
+ A strength of intra-sexual selection is there is research support. Buss (1989) surveyed over 10,000
adults in 33 different countries asking about partner preferences. He found that female’s valued
resource-related characteristics more than males did. Males valued physical attractiveness and youth as
signs of good reproductive capacity more than females did. This supports sexual selection theory.
- A limitation is that evolutionary theories ignore the influences of social and cultural factors on
partner preference. Partner preferences have changed over time due to changing social norms and
cultural practices. These have happened too quickly to be explained in evolutionary terms. Chang et al
(2011) reported that some preferences have changed, and some have stayed the same in the last 25
years in China. Women’s growing role in the workplace means that they are no longer as dependent on
men providing for them. Therefore, Bereczkei et al (1997) argue that women’s mate preferences are
, no longer as resource orientated. This suggests that both evolutionary and cultural influences should be
considered to explain human behaviour.
- A limitation of sexual selection theory is that it cannot explain partner preferences in homosexual
relationships. This is because in homosexual relationships are not assessing genetic fitness or fertility.
Therefore, this theory cannot explain all types of relationships.
+ Another strength is support from waist-hip ratio research. Singh (1993) measured waist-hip ratio
preferences for females and males. They found that any hip and waist size can be seen as attractive
as long as the ratio of one to the other is 0.7. This is because it shows that the female is fertile but
not currently pregnant. This shows that evolutionary factors are reflected in patterns of human
reproductive behaviour through partner preferences.
Self-Disclosure:
- Self-disclosure is revealing intimate information to another person.
- We share fears, interests, and attitudes. This makes our partner understand us better.
- Self-disclosure plays an important role in developing a relationship beyond initial attraction.
- Most people are careful about disclosing too much too soon.
Social Penetration Theory:
- Altman & Taylor (1973) suggests that self-disclosure is limited at the start. It is a gradual process
revealing your inner self to someone else.
- Revealing information about yourself to someone is a sign of trust, the partner then reciprocates this
and reveals personal information. As this happens, they penetrate more deeply into each other’s lives.
- The reverse of this is de-penetration which is when dissatisfied partners self-disclose less because they
disengage from the relationship.
- As the relationship develops, we reveal more intimate information, however not at the start as this
may be off-putting.
Reciprocity of Self-Disclosure:
- Reis & Shaver (1988) suggests that for a relationship to develop there need to be reciprocity in self-
disclosure.
- Once a partner has revealed something, the other partner should respond in a rewarding way, which will
then lead to more self-disclosure from that partner. These increases feelings of intimacy and deepens
the relationship
AO3:
+ A strength of self-disclosure is that there is research support. Sprecher & Hendrick (2004) found a
strong correlation between measures of satisfaction and self-disclosure in heterosexual relationships.
Couples who used self-disclosure were more satisfied and committed to their relationship. This supports
self-disclosure being a key component of committed romantic relationships.
+ Sprecher et al (2013) found that relationships are closer and more satisfying when partners take
turns to self-disclose. This increases the validity of the theory that reciprocated self-disclosure leads to
a more satisfying relationship.
- However, a limitation of research into self-disclosure is that most of it is correlational. A correlation
does not tell us which factor is the cause. We do not know whether partners are in more satisfying
relationships because they self-disclose, or whether people self-disclose more because they are in
satisfying relationships. Alternatively, both of these factors could be caused by a third variable such as
amount of time spent together. This suggests that research provides only limited support for the
theory, this reduces the validity of social penetration theory of self-disclosure.
+ A strength is self-disclosure has real-life applications; it can help people who want to improve
communication in their relationships. Haas & Stafford (1998) found that 57% of homosexual couples
said that open and honest self-disclosure maintained and deepens their relationships. Couples who
communicate through ‘small talk’ can be encouraged to self-disclose in order to deepen their
relationships. This shows that self-disclosure can be used to support people having relationship problems.
Sexual Selection and Human Reproductive Behaviour:
Sexual selection and human reproductive behaviour
- Darwin’s (1871) theory of sexual selection says that
people select characteristics that aid reproduction Self-disclosure
rather than survival. Physical attractiveness
- Females look for signs of genetic fitness in a partner.
- Aggressiveness is adaptive as it gives males an Filter Theory
advantage over competitors for reproductive rights. Social Exchange theory
- Anisogamy is the difference between male and
Equity theory
female sex cells.
- Sperm cells are small, mobile, and continuously Rusbult’s investment model
produced from puberty to old age. Duck’s phase model
- Egg cells are large, static and all formed before birth.
There are only a limited number of fertile years and Virtual relationships in social media
require a significant investment of energy. Parasocial relationships
- The consequence of anisogamy is that there are
plenty of fertile males and fewer fertile females.
Inter-sexual selection:
- Inter-sexual selection is the selection of mates between sexes.
- Females make a greater investment of time and commitment before, during and after birth. Due to
this they need to be choosier than males, so they seek a male who will provide healthy offspring and
support them.
- The traits which are preferred by females are passed on. Height is a marker of genetic fitness in males,
so the females who choose the tallest males will have greater reproductive success and innate
preferences are passed on. This characteristic will then increase in future generations.
- Over time taller and taller men will be selected and this is called the runaway process.
Intra-sexual selection:
- Intra-sexual selection is the selection of mates within sexes.
- Males reproduce as frequently as possible and have to compete with each other for mates as there is a
shortage of fertile females.
- Males who are successful pass on their genes to the next generation.
- Aggression is one of these characteristics as the most aggressive males are more likely to reproduce
- Males also prefer youthful and fertile women because these are signs of fertility leading to reproductive
success.
AO3:
+ A strength of inter-sexual selection is evidence for female choosiness in heterosexual relationships.
Clark & Hatfield (1989) sent students to ask others ‘I have been noticing you around campus. I find you
to be very attractive. Would you go to bed with me tonight?’. None of the female agreed to this,
however 75% of the males did. This supports the view that females are choosier than males, and males
have a different strategy to ensure their reproductive success.
+ A strength of intra-sexual selection is there is research support. Buss (1989) surveyed over 10,000
adults in 33 different countries asking about partner preferences. He found that female’s valued
resource-related characteristics more than males did. Males valued physical attractiveness and youth as
signs of good reproductive capacity more than females did. This supports sexual selection theory.
- A limitation is that evolutionary theories ignore the influences of social and cultural factors on
partner preference. Partner preferences have changed over time due to changing social norms and
cultural practices. These have happened too quickly to be explained in evolutionary terms. Chang et al
(2011) reported that some preferences have changed, and some have stayed the same in the last 25
years in China. Women’s growing role in the workplace means that they are no longer as dependent on
men providing for them. Therefore, Bereczkei et al (1997) argue that women’s mate preferences are
, no longer as resource orientated. This suggests that both evolutionary and cultural influences should be
considered to explain human behaviour.
- A limitation of sexual selection theory is that it cannot explain partner preferences in homosexual
relationships. This is because in homosexual relationships are not assessing genetic fitness or fertility.
Therefore, this theory cannot explain all types of relationships.
+ Another strength is support from waist-hip ratio research. Singh (1993) measured waist-hip ratio
preferences for females and males. They found that any hip and waist size can be seen as attractive
as long as the ratio of one to the other is 0.7. This is because it shows that the female is fertile but
not currently pregnant. This shows that evolutionary factors are reflected in patterns of human
reproductive behaviour through partner preferences.
Self-Disclosure:
- Self-disclosure is revealing intimate information to another person.
- We share fears, interests, and attitudes. This makes our partner understand us better.
- Self-disclosure plays an important role in developing a relationship beyond initial attraction.
- Most people are careful about disclosing too much too soon.
Social Penetration Theory:
- Altman & Taylor (1973) suggests that self-disclosure is limited at the start. It is a gradual process
revealing your inner self to someone else.
- Revealing information about yourself to someone is a sign of trust, the partner then reciprocates this
and reveals personal information. As this happens, they penetrate more deeply into each other’s lives.
- The reverse of this is de-penetration which is when dissatisfied partners self-disclose less because they
disengage from the relationship.
- As the relationship develops, we reveal more intimate information, however not at the start as this
may be off-putting.
Reciprocity of Self-Disclosure:
- Reis & Shaver (1988) suggests that for a relationship to develop there need to be reciprocity in self-
disclosure.
- Once a partner has revealed something, the other partner should respond in a rewarding way, which will
then lead to more self-disclosure from that partner. These increases feelings of intimacy and deepens
the relationship
AO3:
+ A strength of self-disclosure is that there is research support. Sprecher & Hendrick (2004) found a
strong correlation between measures of satisfaction and self-disclosure in heterosexual relationships.
Couples who used self-disclosure were more satisfied and committed to their relationship. This supports
self-disclosure being a key component of committed romantic relationships.
+ Sprecher et al (2013) found that relationships are closer and more satisfying when partners take
turns to self-disclose. This increases the validity of the theory that reciprocated self-disclosure leads to
a more satisfying relationship.
- However, a limitation of research into self-disclosure is that most of it is correlational. A correlation
does not tell us which factor is the cause. We do not know whether partners are in more satisfying
relationships because they self-disclose, or whether people self-disclose more because they are in
satisfying relationships. Alternatively, both of these factors could be caused by a third variable such as
amount of time spent together. This suggests that research provides only limited support for the
theory, this reduces the validity of social penetration theory of self-disclosure.
+ A strength is self-disclosure has real-life applications; it can help people who want to improve
communication in their relationships. Haas & Stafford (1998) found that 57% of homosexual couples
said that open and honest self-disclosure maintained and deepens their relationships. Couples who
communicate through ‘small talk’ can be encouraged to self-disclose in order to deepen their
relationships. This shows that self-disclosure can be used to support people having relationship problems.
