Image: “protest against the Ethiopian-Israeli Jews absorption’s failure.” by האגודה הישראלית למען יהודי אתיופיה. License: CC BY-SA 3.0


Most people like to spend time and form relationships with other people. There is a need to belong and be included by important individuals. Interpersonal attraction relates to how much we like an individual. There are several factors that determine interpersonal attraction, including proximity, interpersonal rewards, similarity and physical attractiveness.


Physical proximity is a simple reason why people spend time with others. People often choose to be friends or partners with those who live close by to them. Proximity enables individuals to get to know each another, and familiarity is linked to liking a person. However, proximity to someone who is disliked initially may lead to increased dislike. Proximity may also change from liking a person to disliking a person. Environmental spoiling occurs when we learn about a person’s bad habits and find that they outweigh good habits and qualities.

Newer research and understanding of proximity indicates that rather than proximity, it is the interaction accessibility that proximity affords that influences attraction.

Interpersonal rewards

The extent to which a relationship or interaction is rewarding is another important determinant of attraction.


Similarities in attitudes, interests and values are an important consideration when people choose their casual acquaintances, friends and best friends.

Physical attractiveness

Physical attractiveness is another factor that influences interpersonal attraction. This does not just apply to romantic relationships, but also applies to acquaintances and friendships. Attractive children are more likely to be popular. Attractive adults receive more assistance from people, better job references and higher pay. They rate their encounters to be more pleasant compared to less attractive people.

With romantic relationships, physical attractiveness is an even more important consideration. The matching hypothesis suggests that people choose partners who they perceive to be just as attractive as themselves.

While standards of beauty differ to some extent between cultures and individuals, the differences aren’t that great when it comes to judging physical attractiveness. Nor are views of beauty specific to any culture.

One theory that has been put forward to explain why physical attractiveness has such an influence on interpersonal attraction is related to neuroscience. When eye contact is made with a physically attractive person, it leads to activation of an area in the brain known as the ventral striatum, which is associated with reward.


Aggression is behavior, physical or verbal, that is intended to harm another person. There are significant variations in the prevalence and types of aggression across different cultures. One of the most consistent features of aggression across cultures is that males are more likely to perpetrate acts of aggression and crime than females. The prevalence of male violence against women, around the world, is being increasingly recognized.

The origins of aggression are still debated. There are theories that stipulate that the origins of aggression are strongly linked to biology and evolution. The regions of the brain primarily controlling aggression are the amygdala, hypothalamus and the frontal lobes. Hormones, especially testosterone, which is a dominant hormone in males, also have a role to play in controlling aggression.

Other theories indicate that social learning and environment play a more important role in aggression. The frustration-aggression hypothesis is a model that indicates aggression occurs as a result of frustrated desires or needs.

A combination of factors is likely to be responsible, captured in the general aggression model (GMA). Based on the general aggression model, aggressive output is determined by variables related to the person and situation.


John Bowlby developed the attachment theory. Attachment refers to the enduring bonds of affection that develop between children and their primary caregivers. It involves a desire for closeness to a person. In the presence of the attachment figure, the child feels secure and in their absence, the child feels distressed. Attachment is not a one-sided relationship. Rather, it is an interactive relationship between the child and caregiver.

Attachment is important for the development of children. Psychoanalysts have found that children who lived in large institutions with little contact to a loving caregiver experienced emotional instability or mental impairment. Children who have minimal attachment may experience such detrimental effects, now called reactive attachment disorder.

John Bowlby compared attachment to imprinting, which is a behavior observed in animals. Imprinting refers to when a young animal recognizes another animal who they were exposed to early in their lives as one to trust and follow. Konrad Lorenz, who studied imprinting, imprinting provides an evolutionary advantage. Immature animals that stay close to their parents are afforded protection and can learn skills for survival and reproduction.

Attachment is a process that is developed over an individual’s lifespan. In infancy, attachment fosters social and emotional development, and during adulthood, it remains important for long-term psychological development. Patterns of early attachment influence attachment in later life. Adult attachment refers to the experience of attachment relationships during adulthood, such as those formed with significant others, family members and friends.


Altruism involves helping other people with no expectation of gain to oneself. In some cases it might involve a personal cost. Examples of altruism include being a blood donor, giving money to the poor or it can be as simple as giving someone directions or giving them a smile.

However, for many years philosophers have debated over whether true altruism exists. Many believe in the concept of ethical hedonism, which is the idea that all behavior is intended to increase one’s pleasure or alleviate one’s suffering. Altruistic actions can result in positive emotions. Negative emotions may be dispelled with a selfless act. Such actions can lead to social rewards such as gratification and thanks from others, or even material rewards such as gifts or awards. Helping people may be a way of avoiding the guilt if one was not to help, or to alleviate empathic distress, where individuals feel negative feelings from empathising with another person in distress.

Alternatively, there are those who believe that genuine altruism exists. The French philosopher Jean-Jacques Rousseau believed that humans possessed natural compassion for other humans. There is some experimental data that supports this idea – that people do, in most cases, opt to help someone who is in distress.

Evolutionary psychologists have proposed another perspective on altruism. They redefine self-interest in terms of reproductive success, and this is expanded to include the reproductive success of related individuals, called inclusive fitness. The evolutionary perspective is that people aim to maximize their inclusive fitness, and so they are more likely to help people who are related to them.

Another significant finding regarding altruism is the bystander effect. Bystander intervention is when an individual helps a stranger who is in distress. However, studies have shown that the presence of others can influence whether a person acts or not. In general, if there are more onlookers in a crisis situation, an individual is less likely to take personal responsibility and act.

Social support

Social support refers to the network of social contacts an individual can rely on in times of stress. People can provide emotional support, information, tangible resources or companionship to help an individual deal with a stressor. As such, social support helps reduce stress or the impact of a stressful event.

Social support is useful for different types of stressors, from a physical illness such as cancer or stroke, to the death of a loved one, discrimination and many others. In addition to reducing stress, social support is associated with health benefits. For example, students with social support have better immune systems and this may account for a lower incidence of sickness during stressful academic periods. Good social support has also been associated with faster recovery in patients who are suffering from an illness or who have undergone surgery. People with a lack of social support are at increased risk of death from an illness and suicide.

A good social support network is more likely to promote happiness, especially if the network is filled with happier people. A social support system provides an avenue to disclose stressful feelings and pent-up thoughts, which may be the reason for its positive effects. Similarly, it is recognized that involvement in support groups for various problems such alcoholism, drug abuse and grief, have benefits for an individual’s health.

The quality of social support is important. Too much support may lead to overprotection from stressors, which can result in poorer coping strategies. Also, in some situations, social networks may encourage negative behaviors such as smoking.

Animal behavior

Foraging behaviors in animals

Foraging behavior refers to behavior that involves searching for, capturing and eating food. Animals have different methods of searching for food, such as active hunting, sitting and waiting, and browsing.

Animals also employ different ways or tactics of obtaining their food. For example, a cheetah stalks its prey, coming within close range before suddenly overtaking it in a quick high-speed chase. Spotted hyena hunting groups chase their prey and overcome them by superior stamina and by working together.

Mating behavior in animals

The first stage of the reproductive cycle in animals is mate selection. This is a process in which an animal of the opposite sex is chosen and a pairing is formed. Mate selection usually occurs in sexually mature animals. However, there are exceptions, such as the pairings that occur among lovebirds who are 2 months old and have juvenile feathers. Likewise, members of the African waxbill species form pairings when the birds are less than 35 days old and are still fed by their parents.

Mate selection involves choosing the right sex and species. Pairings of different species (hybridization) usually results in infertile offspring that fail to adapt to either parent’s ecological niche. Consequently, through natural selection, there are mechanisms that prevent hybridization. These reproductive isolating mechanisms include pre-mating mechanisms, such as ecological, temporal, behavioral and mechanical isolation, as well as post-mating mechanisms that prevent successful interspecific crosses.

Sex selection is important as well. For most species, sexual identification is based on the identification of features that distinguish a male from a female. However, in some cases, there are only a few features to distinguish between the sexes, which is the case with most pigeon species, with the key difference being behavioral.

Following mate selection, courtship often occurs. During courtship, females are typically coy, prolonging the courtship on purpose to test the male and forcing him to work harder on his advances. Courtship is followed by copulation and rearing of offspring.

Different mating strategies exist. Three of the most common types include random mating, in which case there are no spatial, genetic or behavioral limitations and there is high genetic variability; dissociative mating, in which animals often mate those with disparate traits; and assortative mating, which involves non-random mating of animals with similar genotypes or phenotypes.

Applying game theory to animals

Game theory uses mathematical models to make predictions about the behavior of animals with the same interests. An animal requires an overall strategy to achieve success within a game. The strategy includes the goal and a plan to achieve that goal. Animals employ various tactics to achieve the goal.

When tactics are optimal choices, they are called evolutionarily stable strategies (ESS). An ESS is a strategy that cannot be replaced by a new strategy in the population.

The application of game theory requires a number of steps:

  • Identification of possible strategies based on observing animals or logical thinking.
  • Identification of outcomes when different tactics are used.
  • Repetition of the game to determine the ESS.
  • Observation of animals in the field to assess if their behavioral strategies correlate with the predictions obtained from game theory application.

Biological explanations of inclusive fitness and altruism in animals

Inclusive fitness is a measure that assesses the number of animal’s genes present in subsequent generations, as well as the number of genes present in related individuals.

Altruism in animals refers to self-destructive behaviour that is carried out to benefit others. Benefit may be measured in units of inclusive fitness, and as such, an altruistic act would be one that improves the inclusive fitness of other animals at the expense of the individual’s own inclusive fitness. Benefit can also be defined in terms of survival, in which case an altruistic act is one that increases the survival chances of another animal while decreasing one’s own survival chances. Therefore, parental care of an offspring would not be altruistic in regards to inclusive fitness, as this act would increase their inclusive fitness. However, parental care would be altruistic in terms of survival, as the parent decreases their own life expectancy while promoting the survival of the offspring.

Altruistic behavior is also evident in animals that provide care to young animals who are not their offspring but they are related to. For example, some of the nests of Florida scrub jays have ‘helpers’ who are siblings of the young and contribute 30% of their food. These altruistic acts may be seen as ‘selfish’ at the gene level, as the copies of helper genes in the relatives’ bodies are benefitted.


Discrimination may be based on:

  • Race
  • Gender
  • Ethnicity
  • Sexual orientation
  • Age

Individual discrimination refers to the actions of an individual member from one social group with the intention to have a differential or harmful effect on individual from another social group.

Institutional discrimination refers to policies of the dominant institution with the intention to have a differential or harmful effect on the minority group. It includes the actions of individuals who control the dominant institution and implement policies.

The relationship between prejudice and discrimination

The word prejudice literally means “prejudgment”. As a concept, prejudice refers to the attitude directed toward people based on their membership in a specific social group. This attitude may be positive or negative.

Just as attitudes have a cognitive, affective and behavioral component to them, so does prejudice. The cognitive component of prejudice consists of stereotyped thinking. The affective component of prejudices relates to the feelings that individuals harbor toward stereotyped groups, such as admiration, hatred and anger.

Where prejudice is related to discrimination is in its behavioral component. The behavioral aspect of prejudice consists of social discrimination, which involves differential treatment based on an individual’s membership of social group.

How power, prestige and class facilitate discrimination

People in positions of power may seek to maintain their status by employing discrimination against certain groups. Those with an authoritarian trait seek to protect themselves, and to do so, strongly identify with their in-group, while discriminating against and looking down upon out-groups.

Furthermore, those with power, or in a higher-class situation, often have the means to discriminate against those who have less power or are in a lower class.

Review Questions

The correct answers can be found below the references.

1. Which of the following are factors that influence interpersonal attraction?

  1. Physical attractiveness, proximity, and family
  2. Inclusive fitness, altruism and proximity
  3. Proximity, similarity and physical attractiveness
  4. Distance, difference and physical attractiveness

2. What is the meaning of altruism?

  1. Helping one self to benefit other people.
  2. Helping people and benefiting oneself.
  3. Helping people with an intention to alleviate personal suffering.
  4. Helping people with no apparent gain to oneself.
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