Evolutionary psychology is a theoretical approach in psychology that examines cognition and behavior from a modern evolutionary perspective. It seeks to identify human psychological adaptations with regards to the ancestral problems they evolved to solve. In this framework, psychological traits and mechanisms are either functional products of natural and sexual selection or non-adaptive by-products of other adaptive traits.
Sociobiological theories of rape explore how evolutionary adaptation influences the psychology of rapists. Such theories are highly controversial, as traditional theories typically do not consider rape a behavioral adaptation. Some object to such theories on ethical, religious, political, or scientific grounds. Others argue correct knowledge of rape causes is necessary for effective preventive measures.
Parasite load is a measure of the number and virulence of the parasites that a host organism harbours. Quantitative parasitology deals with measures to quantify parasite loads in samples of hosts and to make statistical comparisons of parasitism across host samples.
The Human Behavior and Evolution Society (HBES) is an interdisciplinary, international society of researchers, primarily from the social and biological sciences, who use modern evolutionary theory to help to discover human nature — including evolved emotional, cognitive and sexual adaptations. It was founded on October 29, 1988 at the University of Michigan.
Parental investment, in evolutionary biology and evolutionary psychology, is any parental expenditure that benefits offspring. Parental investment may be performed by both males and females, females alone or males alone. Care can be provided at any stage of the offspring's life, from pre-natal to post-natal.
A psychological adaptation is a functional, cognitive or behavioral trait that benefits an organism in its environment. Psychological adaptations fall under the scope of evolved psychological mechanisms (EPMs), however, EPMs refer to a less restricted set. Psychological adaptations include only the functional traits that increase the fitness of an organism, while EPMs refer to any psychological mechanism that developed through the processes of evolution. These additional EPMs are the by-product traits of a species’ evolutionary development, as well as the vestigial traits that no longer benefit the species’ fitness. It can be difficult to tell whether a trait is vestigial or not, so some literature is more lenient and refers to vestigial traits as adaptations, even though they may no longer have adaptive functionality. For example, xenophobic attitudes and behaviors, some have claimed, appear to have certain EPM influences relating to disease aversion, however, in many environments these behaviors will have a detrimental effect on a person's fitness. The principles of psychological adaptation rely on Darwin's theory of evolution and are important to the fields of evolutionary psychology, biology, and cognitive science.
Mate choice is one of the primary mechanisms under which evolution can occur. It is characterized by a "selective response by animals to particular stimuli" which can be observed as behavior. In other words, before an animal engages with a potential mate, they first evaluate various aspects of that mate which are indicative of quality—such as the resources or phenotypes they have—and evaluate whether or not those particular trait(s) are somehow beneficial to them. The evaluation will then incur a response of some sort.
On Human Nature is a book by the biologist E. O. Wilson, in which the author attempts to explain human nature and society through sociobiology. Wilson argues that evolution has left its traces on characteristics such as generosity, self-sacrifice, worship and the use of sex for pleasure, and proposes a sociobiological explanation of homosexuality.
Evolution of Infectious Disease is a 1993 book by the evolutionary biologist Paul W. Ewald. In this book, Ewald contests the traditional view that parasites should evolve toward benign coexistence with their hosts. He draws on various studies that contradict this dogma and asserts his theory based on fundamental evolutionary principles. This book provides one of the first in-depth presentations of insights from evolutionary biology on various fields in health science, including epidemiology and medicine.
A Natural History of Rape: Biological Bases of Sexual Coercion is a 2000 book by the biologist Randy Thornhill and the anthropologist Craig T. Palmer, in which the authors argue that evolutionary psychology can account for rape among human beings, maintain that rape is either a behavioral adaptation or a byproduct of adaptive traits such as sexual desire and aggressiveness, and make proposals for preventing rape. They also criticize the assumption that there is a connection between what is naturally selected and what is morally right or wrong, which they refer to as the "naturalistic fallacy", and the idea, popularized by the feminist author Susan Brownmiller in Against Our Will (1975), that rape is an expression of male domination and is not sexually motivated.
The behavioral immune system is a phrase coined by the psychological scientist Mark Schaller to refer to a suite of psychological mechanisms that allow individual organisms to detect the potential presence of infectious parasites or pathogens in their immediate environment, and to engage in behaviors that prevent contact with those objects and individuals.
Ecoimmunology or Ecological Immunology is the study of the causes and consequences of variation in immunity. The field of ecoimmunology seeks to give an ultimate perspective for proximate mechanisms of immunology. This approach places immunology in evolutionary and ecological contexts across all levels of biological organization.
A biological ornament is a characteristic of an animal that appears to serve a decorative function rather than a utilitarian function. Many are secondary sexual characteristics, and others appear on young birds during the period when they are dependent on being fed by their parents. Ornaments are used in displays to attract mates, which may lead to the evolutionary process known as sexual selection. An animal may shake, lengthen, or spread out its ornament in order to get the attention of the opposite sex, which will in turn choose the most attractive one with which to mate. Ornaments are most often observed in males, and choosing an extravagantly ornamented male benefits females as the genes that produce the ornament will be passed on to her offspring, increasing their own reproductive fitness. As Ronald Fisher noted, the male offspring will inherit the ornament while the female offspring will inherit the preference for said ornament, which can lead to a positive feedback loop known as a Fisherian runaway. These structures serve as cues to animal sexual behaviour, that is, they are sensory signals that affect mating responses. Therefore, ornamental traits are often selected by mate choice.
Sexual suggestiveness is visual, verbal, written or behavioral material or action with sexual undertones implying sexual intent in order to provoke sexual arousal.
The Evolution of Human Sexuality is a 1979 book about human sexuality by the anthropologist Donald Symons, in which the author discusses topics such as human sexual anatomy, ovulation, orgasm, homosexuality, sexual promiscuity, and rape, attempting to show how evolutionary concepts can be applied to humans. Symons argues that the female orgasm is not an adaptive trait and that women have the capacity for it only because orgasm is adaptive for men, and that differences between the sexual behavior of male and female homosexuals help to show underlying differences between male and female sexuality. In his view, homosexual men tend to be sexually promiscuous because of the tendency of men in general to desire sex with a large number of partners, a tendency that in heterosexual men is usually restrained by women's typical lack of interest in promiscuous sex. Symons also argues that rape can be explained in evolutionary terms and feminist claims that it is not sexually motivated are incorrect.
Mate preferences in humans refers to why one human chooses or chooses not to mate with another human and their reasoning why. Men and women have been observed having different criteria as what makes a good or ideal mate. A potential mate's socioeconomic status has also been seen as having a noticeable effect, especially in developing areas where social status is more emphasized.
In evolutionary psychology and behavioral ecology, human mating strategies are a set of behaviors used by individuals to select, attract, and retain mates. Mating strategies overlap with reproductive strategies, which encompass a broader set of behaviors involving the timing of reproduction and the trade-off between quantity and quality of offspring.
Parasite-stress theory, illustrated by researchers Corey Fincher and Randy Thornhill, is a theory of human evolution proposing that parasites and diseases encountered by a species shape the development of species' values and qualities. The differences in how parasites and diseases stress people's development is what leads to differences in their biological mate value and mate preferences, as well as differences across culture. Parasites causing diseases pose potential ecological hazards and, subsequently, selection pressures can alter psychological and social behaviours of humans, as well as have an influence on their immune systems.
Pathogen avoidance, also referred to as, parasite avoidance or pathogen disgust, refers to the theory that the disgust response, in humans, is an adaptive system that guides behavior to avoid infection caused by parasites such as viruses, bacteria, fungi, protozoa, helminth worms, arthropods and social parasites. Pathogen avoidance is a psychological mechanism associated with the behavioral immune system. Pathogen avoidance has been discussed as one of the three domains of disgust which also include sexual and moral disgust.
In humans, males and females differ in their strategies to acquire mates and focus on certain qualities. There are two main categories of strategies that both sexes utilize: short-term and long-term. Human mate choice, an aspect of sexual selection in humans, depends on a variety of factors, such as ecology, demography, access to resources, rank/social standing, genes, and parasite stress.
