biological theory of attraction

evolution

sexual selection

natural selection

those who adapt best to their environment have a greater chance of surviving, producing offspring and passing down genes

adaptation

beneficial characteristics and traits survive in a particular species, makes them more competitive in their environment

* advantageous genes are passed down from generations

sexual selection

* sexual selection is a critical part of a natural selection → one biological sex chooses mates of the other sex to produce offspring (intersexual selection)
* \

intrasexual selection

members of the same sex (usually males - but it can differ) compete which each other for access to members of the opposite sex

intersexual selection

members of one sex (usually females) choose members of another sex based on a specific characteristic - eg dance, great feathers or an amazing jawline

what are humans most attracted to according to theory

humans are attracted to partners that produce the most healthy offspring

major histocompatibility gene

* human immunity - codes for how well the immunity of offspring would be
* co-dependent gene, diversity within the MHC gene of both mates = offspring with strong immune system


* mates will be attracted to those with MHC genes most dissimilar to theirs to produce strong offspring

attraction

physical appearance and behaviours of the individual, biological → hormones, neurotransmitters and maybe even pheromones

* eg testosterone (hormone) present in males, responsible for physical traits

ronay and von hippel 2010 aim

to see whether the presence of an attractive female would cause male skateboarders to take greater risks in correspondence with testosterone levels, than in the presence of a male.

ronay and von hippel 2010 method

repeated measures design but also indepedent samples design

ronay and von hippel 2010 procedure

* sample was 96 young adult australian male skateboarders with a mean age of 21 recruited w opportunity sampling
* participants were recruited at skateboard parks
* 2 conditions
* 43 assigned to male-researcher condition
* 53 assigned to the female-researcher condition
* tests were conducted between 2 and 6 pm
* skateboarders were asked to do one “easy trick” and one difficult trick which they could successfully complete approximately 50% of the time - asked to do each trick 10 times
* after a break, they were asked to make 10 more attempts of each trick but this time in front of the same male researcher or an attractive 18-year-old female researcher who was blind to the hypothesis
* the attractiveness of the researcher was established by having 20 male raters view photos of potential female experimenters
* the skateboarders’ attempts were coded for one of three outcomes: success, crash landing or aborted attempt
* high levels of aborted attempts would be seen as an indicator of low-risk taking
* saliva samples were also collected to measure testosterone. heart rate was measured by having participants wear a nordic sports watch
* measurements were taken immediately before the test and then measured throughout the task

ronay and von hippel 2010 results

* participants took greater risks on the difficult tricks in the presence of the female researcher - they aborted the trick fewer times
* in addition, testosterone levels were higher in the men that skateboarded in front of the female researcher than in front front of the male researcher
* there was no significant difference in the measure of heart between the two groups
* the study showed that young men take great physical risks when in the presence of an attractive woman and that testosterone may account for this behaviour
* according to evolutionary theory, this makes sense. the increased risk-taking is a sign to potential mates that the male is healthy, strong, and dominant - that is, would be able to intimidate any potential rival

ronay and von hippel 2010 strengths

• experiment is well-controlled. the attractiveness of the females researcher, the time of day, and the heart rate were all controlled in this experiment

• establishes cause and effect relationship- by manipulating the gender and attractiveness of the experimenter, the researchers attempted to establish a causal link between these factors and the observed changes in testosterone levels and risk-taking behavior

• the experiment was also conducted under highly naturalistic conditions → leading to high ecological validity

• demand characteristics are low

  • no variables were manipulated

• Controlled variables

  • Attractiveness was rated on criteria testosterone was sampled and even heart rate was measured

  • High internal validity

• female researcher was blind to the conditions - reduces demand characteristics - might act in a certain way unknowingly

ronay and von hippel 2010 limitation

• Sampling bias

  • Young Australians, cultural bias

  • Cannot be generalized to larger populations

• Ethical issue of deception

  • Participants did not know they were being tested for mating behavior - may be potentially embarrassing when debriefed however they would have had the right to withdraw their data

• Reductionist

  • Does not value sociocultural factors

• the design was a repeated measures design. order effects - eg fatigue could have influenced the findings.

  • it was also an independent samples design in that some had a female in the second set and some had a researcher. - variability is high

• tricks that were tried in both groups cannot be standardised for '“difficultly” this questions the validity of the measure of “aborted tries” as a sign of risk-taking

• this could potentially be an example of intrasexual selection, however it is difficult to establish that reproduction is the goal of the behaviour

wedekind 1995 aim

study the MHC gene relevancy on mate selection

wedekind 1995 procedure

* sample of university students, 49 females and 44 males, typed for MHC gene - wide variance of MHC was included in the sample 0 women were from different courses - probs didn’t know each other as they were from different courses
* Male participants - asked to wear tshirt for two nights, refrained from using products that altered their natural odor, perfume, smoking, spicy foods, soap deodorant etc and to not engage in any sexual activity
* t shirt sealed in a plastic bag during the day and put in a box for the experiment
* female participants asked for health backgrounds and uses of oral contraceptives that alter with hormones
* women were asked to prepare themselves by using a nose spray for the 14 days before the experiment to support the regeneration of nasal mucous membrane if necessary - as a preventive measure against colds or flu.
* females asked to smell seven different tshirts during menstrual cycle - each in a cardboard box with a “smelling hole”
* the women were tested whenever possible in the second week after the beginning of menstruation, as women appear to be most oder-sensitive at the time
* two dissimilar MHC
* two similar MHC
* one control
* shirts ranked by attractiveness from smell

wedekind 1995 findings

* women ranked dissimilar MHC shirts as more attractive, and similar MHC as more unpleasant
* this difference in odor assessment was reversed when the women rating the odors were taking oral contraceptives. this suggests that the MHC may influence human mate choice.

wedekind 1995 conclusion

* MHC genes are codominant, many variations will help with offsprings immune system 


* Just from the smell, women selected partners that would produce the most healthy offspring, supporting evolutionary theory. 

wedekind 1995 strengths

* High internal validity
* Controlled laboratory experiment
* The controlled laboratory setting allows researchers to manipulate variables precisely and control potential confounding factors. This increases the likelihood that changes in the dependent variable (mate preferences in this case) can be attributed to the independent variable (genetic differences) with greater confidence.
* Reliable
* Easy to replicate and would get similar results
* The study's experimental design and procedures are relatively straightforward, making it easy for other researchers to replicate the study and test the same hypotheses.

wedekind 1995 limitations

* sample bias (homogeneity of sample - limited cultural variation)
* only university students, small sample size
* The study's reliance on university students from a specific region introduces a potential cultural bias. Different cultures have distinct norms and values that shape mate preferences. The homogeneity of the sample restricts the generalizability of findings to a global context and limits our understanding of how cultural diversity impacts mate selection.


* reductionist
* only looks at biological arguments
* The study primarily focuses on genetic differences influencing scent preference and mate choice. While genetics play a role, human mate preferences are also influenced by cultural, psychological, and social factors. Neglecting these other dimensions could oversimplify the complex nature of human mate selection.
* Low external validity
* Unrealistic, not applicable in nature
* The study's controlled laboratory environment contrasts with the complex and multifaceted nature of human mate selection. The controlled setting isolates the impact of scent on mate preferences, but it fails to account for the wide range of factors that come into play during real-world interactions. The disconnect between the controlled environment and natural contexts might limit the study's external validity. People's choices in a controlled laboratory environment might differ from those made in natural social contexts, where emotions, personal histories, and other contextual cues play a significant role.
* Biological Determinism - Oversimplification of Mate Choice
* While the study effectively examines scent preferences in relation to MHC genes, it focuses exclusively on one biological aspect. This narrow scope disregards the intricate interplay of other factors such as personality traits, shared interests, and social dynamics that contribute to mate choices. The study's isolation of a single variable might oversimplify the complexity of real-life mate selection.

evaluation of biological theory of attraction

• Dependent on assumption that all behaviour is inherited through genes

  • Not always true due to methylation and acetylation patterns

    • While genetics play a crucial role in shaping behaviour, the assumption that all behaviour is solely inherited through genes oversimplifies the complex nature of gene expression. - difficult to know to what extent behaviours are actually genetically inherited.

    • Epigenetic mechanisms, such as DNA methylation and histone acetylation, can influence how genes are activated or silenced, leading to variations in behaviour that are not purely genetic. This challenges the theory's deterministic stance.

• Assumption - mating behaviours are universal through all cultures and ages

  • Theory cannot be holistic, follows a reductionist argument that is biased towards evolution only

    • Assuming that mating behaviours are universal across all cultures and ages overlooks the influence of cultural norms, values, and historical contexts on relationship dynamics.

    • The theory's reductionist bias towards evolution can limit its ability to account for the rich diversity of human behaviors that shape attraction and mate selection beyond biological factors.

• Cannot predict behaviour, reality of attraction is different outside of controlled laboratory procedures where extraneous variables are eliminated

  • The theory's reliance on controlled laboratory experiments might not capture the complexities of real-world attraction dynamics. In everyday life, numerous extraneous variables come into play, such as personal experiences, social contexts, and emotional responses, which can significantly impact how attraction and mate selection occur. - difficult to empirically test evolutionary theories - making researchers susceptible to confirmation bias

• Cannot be applied in all contexts -> assumptions that say animal behavior is connected to human behaviour

  • Genetic and physical similarities exist, although the behaviour cannot be the same

    • While there are genetic and physical similarities between humans and animals, assuming a direct link between animal behaviour and human behaviour oversimplifies the distinctions between the two.

    • Humans possess unique cognitive, emotional, and social complexities that influence attraction and relationship dynamics beyond the scope of purely biological factors.

• No cause and effect relationship, mostly correlational in nature.

  • The biological theory of attraction often relies on correlational studies that identify associations between genetic factors and attraction-related behaviours.

  • However, these studies cannot establish a cause-and-effect relationship.

  • While they provide insights into potential connections, they do not definitively prove that genetic factors directly cause specific attraction behaviours.

• Neglect of Individual Differences - Variation in Genetic and Behavioral Influences:

  • The theory's focus on genetics might overlook the considerable variability in how individuals respond to biological and environmental factors.

  • Factors such as personality traits, life experiences, and personal preferences can lead to variations in attraction and mate selection even among individuals with similar genetic backgrounds.