# Motivation and mate-seeking

* Multimedia presentation (5 min)

## Overview and Topic Relevance

You may be asking yourself why is this topic relevant? One only has to look as far as their closest night-spot to observe that all cultures are consumed by the notion of seeking out a suitable mate. Alternatively you could ask yourself, what is the function of bars and clubs, internet dating, dancing and men's and women's magazines? Is it all just one big ritual to impress the opposite sex?
A lot of time, effort, and money is spent on considering and subsequently enhancing our sexual attractiveness in an effort to achieve a suitable partner. In the 21st century our whole society, it seems, is geared towards couple mentality. Socio-economic factors such as rising house prices, home loans, and a need to attain wealth and luxury items such as a fancy house, or car, make pairing almost a necessity. Our global economy is fuelled by this trend, whether it is measured by means of cosmetic surgery, weight loss or by the trillion dollars spent on make-up every year, it seems physical attractiveness is a very important element of who we are and how we attract a prospective mate. But are we merely slaves to our basic animal instincts or are we highly evolved rational beings?
Sociocultural factors such as gender roles and practices may also have a large impact. Ask yourself, when was the last time you remember being taught to, man up, or act more lady like in the presence of the opposite sex? Do you remember as a child, reading stories or seeing movies that ended in prince charming sweeping the princess off her feet and riding off into the sunset? These cultural expectations have an enormous impact on our mate seeking preferences, how we choose our partner and whom we choose to partner with. But what motivates us as humans to behave in this way? What drives us to seek out a suitable mate? And what makes this mate suitable? These questions will be discussed in the subsequent article.

## Human and Animal Research

Partner selection has historically fascinated poets, musicians and playwrights alike and has laid the foundation for a complex social system of marriage and partnership for generations across all civilisations (More 2010). However it was not until early theories of Darwin in the mid 1800s, focusing on natural selection and mating preferences of animals (Darwin 1859), that mate seeking behaviour was empirically studied and recognised as a scientific concept. It is this evolutionary perspective that dominates the majority of psychological research and theory of mate seeking behaviour. Consequently a lot of what we know about human intrinsic motivation is derived from animal research.

## The Evolutionary Approach to Mate Seeking Behavior
### The Evolutionary Approach

Darwin believed that sexual selection impacted greatly on the evolution of humans and the diversity of a population (Encyclopedia 2010). According to Darwin, sexual selection is the advantage of individuals over others of the same sex and species in the population to reproduce (Jones and Ratterman 2009).
Darwin's theory consisted of two main premises:
* The law of battle – whereby the strongest wins the right to reproduce
* Female or male choice – whereby the desired trait is passed on to the next generation
Modern conceptions of Darwin's model have further theorized the possible reasons as to why this is so (Shuster 2009).
Darwin Fisher Model of Sexual Selection – purports that higher quality female’s breed before lower quality females as they choose to pair with higher quality males. According to Darwin this serves a functional purpose as they produce more offspring as the higher quality males are able to fend off threats.
The Direct Benefits Model - assumes that females choose their mate based on the benefits their partner brings – such as nurture and care for their offspring, protection and resourses at ther disposal.
The Model of Indirect Benefits - hypothesizes that females base mate selection on the basis of a trait which predicts genetic success and that the ornament serves as a predictor of genetic variation.

### Some Common Criticisms of the Evolutionary Approach

The approach while extremely parsimonious does not account for all mate seeking behaviors in humans. The theory is also based on the explanation of female preferences in mate selection, and males tack a back seat in the selection of a mate. The approach is extremely controversial as innate concpets cannot be easily tested in humans and as such the heuristic value of the theoretical approach has been questioned. The approach also neglects the role of the environment in evolution, favoring genetic explanations (Shuster 2009),( Jones and Rattermann 2009) and (Yoshida, Dolan, Friston 2008).

## Evolutionary Approach and Recent Evidence

Evidence suggests that mate selection could be influenced more than we might think by unconscious genetic processes (Kaplan and Oudeyer 2007 a) This hypothesis has evolved from a growing body of evidence supporting the notion that factors such as body odour functions to discriminate partners with dissimilar immunity allells, in order to produce offspring with a highly varied and therefore larger resistance to environmental pathogens (Derti et al 2010).
A study on a the Major Histocompality complex, a region of immunity genes, found that American European couples had larger MHC locus dissimilarity than non couples. However found that a study on a Yoruban (West African population) believe that due to outliers in the data this finding was not robust to conclude that immunity genes influence mate selection. This recent examination finds that rare instances of extreme gene similarity were avoided, rather partners choose partners similar to themselves however not so similar that they risk genetic inbreeding (Kaplan and Oudeyer 2007 a).
Some animal studies have identified chemicals essential to pairing and bonding behaviour in pairing. Liu et al (2010) found that drug exposure on a monogamous rat species can manipulate the bond between rodent pairs. Repeated exposure to a AMPH drug induced repeated exposure impaired the bond behavior between the rats, suggesting possible evidence for the nucleus accumbens in the release of chemicals such as dopamine essential for boding between monogamous species. Kokko and Rankin (2006) suggest that availability of potential mates is a ecological factor that is often overlooked by evolutionary theorists. However many researchers argue that population density may play a large role in competition, and female choice. Females are unlikely to reject an unfit male if there is not another alternative.

## The Relevance of Darwin's Theory in Adaptive Mate Choice

Male mate preference behaviour in humans has received significantly less attention as animal research predominantly focuses on the female mate preference behaviour. However some recent research suggests that Darwin’s theory of natural selection is less relevant when applied to species where the male chooses a mate. Research has shown that male selection is counter intuitive to the notion of evolutionary driven mating preferences (Hall, Lindholm and Brooks 2004). A recent study on antagonistic male mating preferences in melangaster flies by long et al (2009) concluded that antagonistic and persistent behaviour of males in the selection of a mate decreases the efficacy of beneficial genetic variation. As males exhibit a mate preference for females with a high capacity to reproduce (those with larger body size), this reduces the female’s capacity to choose a mate that is beneficial to genetic variation. The antagonistic and persistent nature of the behaviour makes it easier for the male to select and reproduce with a female who has a lower fitness level (smaller body size). As this type of mate selection favours reproduction in lower fitness females the overall fitness of the population decreases and regresses towards the mean (Hall, Lindholm and Brooks 2004). As this is a relatively new finding, more research needs to be conducted to see if it is generalisable to other species and populations.

## Adolescence and Learning Mate Preferences

Adolescence is a particularly interesting time from a research point of view as it is widely agreed upon that many individuals begin to develop an interest in the opposite sex. Studies on mate selection involving adolescents give researchers the opportunity to observe the formulation and possible causal factors associated with partner selection. From a learning theorists point of view, early adolescence is a time where the socialization of mate selection is formed, developed and continues to play an important role in development (Bartels, Magun-Jackson & Ryan 2010). Partners have been found to have similar social habits such as alcohol consumption and similar emotional intelligence (Amitay and Mongrain 2007). Adolescents not only choose a partner similar to themselves but their drinking behaviors tend to converge (Zwaluw et al 2009). A study by Simon, Aikins and Prinstein (2008) on the assessments of adolescent and romantic partner adjustment found that characteristics of a partner in adolescence strongly mediated psychosocial functioning of their partners. Prior to the relationship partners were self reportedly and peer reportedly alike on several facets including popularity, physical attraction and depressive symptoms. During the course of the study victimization significantly predicted change participants level of functioning, however this was largely dependent on the partners functioning, which predicted the direction and significance of the effect (Simon, Aikins and Prinstein 2008). This supports the notion that partner selection may be motivated by likeness traits, which further develop our experiences in early adolescence (Simon, Aikins and Prinstein 2008).

## Social Transmission of Mate Preferences

Recent evidence lends support to the notion that partner preference may be socially transferable among animal and human populations providing support for the notion that mate seeking may be adaptive and learned.

### Animal Studies

Is it possible that animals can mediate the effects of evolution through cultural learning? Evidence suggests that some species can acquire mate preferences through social mechanisms by means of observation and copying behaviors in the acquisition of a mate. This posits the notion that this behavior may influence the selection of specific traits in a partner and thus the future traits of the population. In 2005 a study on a polygamous species of sparrow by Swaddle and colleuges found, females developed preferences for males who had previously been chosen by other females. A second experiment revealed this effect generalized not only to the specific mate but also to a trait characteristic of the partner. Female sparrows chose mates that they had previously seen with other females exhibiting the same characteristic such as a leg band. [File:Sparrow portrait.jpg|Sparrow portrait|thumb|200|Female Sparrows develop preferences for male sparrows with previous experiance]]]

### Human Studies

Recent evidence has suggested that social transmission of mate choices may also exist in humans. A study by Jones and colleuges in 2007 showed that women who saw other women exhibiting positive facial expressions towards men such as smiling, increased the woman’s preferences to a male more than neutral expressions. Men however exhibited the opposite effect supporting the hypothesis that males may see this as a sign of competition from other males.
Mate copying behavior in humans is thought to function as a valuable source of knowledge which informs our own choice. Yorzinski and Platt in 2010 found that men and women both expressed interest in a photograph of a potential mate of the opposite sex when the potential mate was pictured as being paired with an attractive partner of the opposite sex. Women however showed a greater reliance on the partner choices of other women. It is hypothesized that as women are generally more selective than males (Yorzinski & Platt 2010) they may be more suspicious of males who are paired with a less attractive mate due to differential parental investment. Females are unlikely to pair with a partner they do not believe is capable of relative success with other attractive females.

## Sex Differences in Selectivity

A lot of research has focused on the differences between male and female mate selection and courtship behaviour. Approaching a potential mate, a characteristic of males observed in many studies has found to be a mediating factor of attraction (Finkel and Eastwick 2009). A speed dating study by Finkel and Eastwick (2009) found that the act of merely approaching, rather than reacting to an approach, produced significantly lower levels of choosiness in men as it increases attraction to the partner, however this same effect was not found in women. This is theorised to be dependent upon intrinsic desire of the male to approach the female in situated conceptualisation (Harris and Uller 2009). This theory suggests general categories become more meaningful when they are paired with a context. Therefore approach behaviour in a romantic context makes the behaviour more meaningful for the person approaching and thus more confidence in speed dates and around potential mates of the opposite sex. However when the roles were reversed and women became rotators, this effect in men diminished. Partners perceptions of mate preference are not the only important factor in mate selection. Recent research has suggested that perceptions of the self or self concept, a phenomenon theroised to evolved due to selection pressure in the environment, can also impact on the mate selection preferences of men and women (Campbell and Wilbur 2009). This is believed to reflect the values of the mate preferences of the opposite sex. A series of studies by Campbell and Wilbur (2009) found that traits related to men’s status and resources were an important aspect of men’s self concept and that women placed more importance on traits such as physical attractiveness on their self concept.

### Males

Many studies have found that males are less selective when choosing a potential partner when compared with females (Finkel and Eastwick 2009). Men have also been found to place more emphasis on perceived beauty and youth (Campbell and Wilbur 2009) and seek women who have a high chance of reproductive success (Todd et al 2007). Studies have also found that men felt more threatened by other males who were perceived to have higher levels on traits related to status and resources (Campbell and Wilbur 2009). Many studies have found that males place more emphais on the sexual fidelity of their partners, whereas women place more emphais on the emotional fidelity of partners (Josephs & Shimberg 2010). This is thought to occur as males want to be sure that any offspring a mate produces is their biological product (Josephs & Shimberg 2010).

### Females

Studies have found women place more emphasis on status and resources than other traits (Campbell and Wilbur 2009). This is hypothesized to occur as the evolutionary theoretical assumption stipulates that men and women have differentaial levels of parental investment (Kaplan and Oudeyer (2007 b). Women have also been found to be more threatened by rivals who appeared higher on levels of traits related to attractiveness (Campbell and Wilbur 2009), which may occur due to both self concept and/or the potential for successful pairing with a mate of the opposite sex.

## Actual And Perceived Mate Selection

Many studies using self-report measures have not supported the evolutionary theory as they found that simeralities amoung individuals highly correlated with attraction levels. However it has been argued that self report measures do not accurately reflect an individuals actions (Toddet al 2007). Preferred characteristics and actual characteristic of the ideal partner may also differ due to competition (Courtiol et al 2010). Consistent with this hypothesis, a study by Courtiol et al (2010), examine the actual and desired body type preferences of couples in france concluded that actual characteristics differ to preferred characteristics of an individuals partner for males but not for females. Traits considered to be highly predictive of atractivness in a mate may not be predictive of a actual mate selection and pairing (Henecy et al 2008). For women a weak correlation was found between desired and actual physical attractivness of their partner. While for men a strong correlation was found between desired and actual physical attractivness of their partner. For example men who prefer larger women, usually have a larger than average partner. This demonstrates that the influence of desired physical traits on selection of a partner may be sex specific.
A speed dating study by Toddet al (2007) on adults found that questionares or self report measures were a reliable measure of the belief that an individual was attracted to a mate similar to them. However this belief did not translate into action when actual preferences were observed as male’s tended to choose women based on their physical attractiveness levels. Women tended to be more discriminative and choose men based on their overall desirability as compared to the woman’s level of attractiveness (Todd et al 2007).

## Attraction

Attractive traits are theoretical signifyers of underlying health and reproductive capacity of a potential mate (Gallap and Fredrick 2010). Two types of searching strategies in humans have been examined (Henecy et al 2008). Confirmation searching refers to information seeking about a potential mate. An individual may choose to ask questions to affirm or negate their beliefs about the individual to determine whether they are an appropriate mate. A balanced search strategy involves risk assessment of the partner (Henecy et al 2008). A study by Henecy et al (2008) of college students found little evidence for the occurrence of a balance search strategies as when participants viewed various vignettes of a made up person they predominantly searched for information on attractiveness levels. There was no difference found between males and females for the attainment of information aboput the level of attractiveness or risk information. however when the participants were presented with a vignette of an unattractive persona – additional information was a significant factor. These results do not confirm the hypothesis that people conduct a balanced well thought out approach to seeking a mate but rather they seek out what they are attracted to in a mate.

### Attractive Similarity or Differences

Studies on women’s face preferences of males have found highly variable results on what women consider to be attractive. This is partly due to the way the faces were manipulated across studies. A study by DeBruine et al (2006) using a technique integrating three of the most widely used face techniques, to manipulate facial images, revealed women's face preferences for masculine faces positively correlated with the masculinity of their ideal and actual partner. These results demonstrate the large variability in the perceived trait attraction of a partner. However Gallap and Fredrick (2010) suggest that although there is large varaility between the attraction of traits and individuals there is an overall consensus for some traits.

### Menstrual Cycle

Many studies have detailed that a woman is more attractive to potential mates when she is at her most fertile. However recent studies have contradicted the assumption that women are more visually physically attractive during the more fertile stages of their menstral cycle as Peters, Simmons and Rohdes (2009) found no significant effect for differences in attractiveness ratings for photographs of women at various stages in their menstral cycle. These did not differ between low and high fertility phases either. This suggests that a visual stimuli may be too subtle to detect differences in a woman’s appearance (Peters, Simmons and Rohdes 2009).

### Social Status

The social status of a male or female can also be predictive of reproductive success (Shulster 2009). It has been widely observed, particularly in social animals, that those with alpha female or alpha male status are more likely to produce more offspring and have the first pick of a mate (DuVal and Kempenaers 2008). This finding is also indicative of the higer levels of attraction of both female and males when self confidence in a potential mate is high (Kaplan and Oudeyer 2007b).

### Waist to Hip Ratio

Waist to hip ratios and shoulder to hip ratios have widely been found to be a preditor trait of attraction (Gallap and Fredrick 2010). The hour glass figure in women is more attractive due to perceived reporoductive associations such as the frequency of ovulation – women with hourglass figures generally ovulate more often and have a more consistent cycle. The loss of this hourglass figure is seen to be an adaptive indicator of pregnancy and thus incapacity at that stage to conceive (Peters, Simmons and Rohdes 2009). Broad skeletal mucle in women is also attractive as they can undergo birth and lower body fat in women is indicative of gulteofermoraol fat which aids in neural development (Gallap and Fredrick 2010), and thus reproductive success.