Related Experiment Video
Updated: Jul 8, 2026
07:19
A New Approach that Eliminates Handling for Studying Aggression and the "Loser" Effect in Drosophila melanogaster
Published on: December 30, 2015
The Evolution of Human Homosexual Behavior.
Current Anthropology
|April 18, 2000
Summary
Homosexuality may have evolved through reciprocal altruism, where same-sex alliances offer reproductive advantages. This challenges kin selection and supports parental manipulation as less likely evolutionary drivers.
Area of Science:
- Evolutionary Psychology
- Anthropology
- Behavioral Biology
Background:
- Homosexuality presents an evolutionary paradox, challenging traditional views of adaptation measured by reproductive success.
- Understanding the evolutionary origins of non-reproductive behaviors like homosexuality is crucial for behavioral science.
Purpose of the Study:
- To review and compare three adaptationist hypotheses for the evolution of homosexuality.
- To assess the validity of kin selection, parental manipulation, and reciprocal altruism in explaining homosexual behavior.
Main Methods:
- Review of existing adaptationist hypotheses.
- Comparison of hypotheses with anthropological and primatological literature.
- Analysis of evidence for reproductive advantages of same-sex alliances.
Main Results:
- Little evidence supports kin selection; homosexual members do not appear to confer lineage reproductive advantages through offspring care.
- Moderate support exists for parental manipulation, as parents sometimes influence children's reproductive decisions and homosexual behavior.
- Strongest support is for reciprocal altruism, where homosexual behavior maintains beneficial same-sex alliances, observed in nonhuman primates and potentially early humans.
Conclusions:
- Homosexual behavior is partly an emergent quality of human same-sex affiliation, with reciprocal altruism offering the most compelling evolutionary explanation.
- While adaptationist explanations are valuable, they do not fully account for human sexual behavior, highlighting the role of social and historical factors.
Related Concept Videos
02:31Synteny and Evolution
John H. Renwick first coined the term “synteny” in 1971, which refers to the genes present on the same chromosomes, even if they are not genetically linked. The species with common ancestry tend to show conserved syntenic regions. Therefore, the concept of synteny is nowadays used to describe the evolutionary relationship between species.
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral chromosome underwent...
Around 80 million years ago, the human and mice lineages diverged from the common ancestor. During the course of evolution, the ancestral chromosome underwent...
01:20Evolutionary Psychology
Evolutionary psychology explores the origins of human behavior and mental processes by framing them within the context of natural selection, a theory famously propounded by Charles Darwin. This field asserts that many behaviors common across human societies — ranging from instinctive fear reactions to complex social interactions — arose as evolutionary adaptations. These adaptations enhanced the survival and reproductive success of our ancestors, thereby becoming embedded in the human psyche...
01:06Natural Selection and Mating Preferences
The principle of natural selection posits that organisms better adapted to their environment are more likely to survive and reproduce. This principle is closely intertwined with mating preferences, a key aspect of sexual selection, which evolutionary psychologists believe is driven by instincts to propagate one's genes. Such instincts significantly influence mating behaviors and preferences between genders.
Females, due to their biological roles in conception, pregnancy, and nursing, inherently...
Females, due to their biological roles in conception, pregnancy, and nursing, inherently...
01:23Criticisms of the Evolutionary Perspective
In a study where individuals posing as strangers offered compliments and proposed casual sex to students, the responses differed significantly based on gender. Not a single woman accepted the proposal, while 70% of the men agreed. This outcome provides a useful scenario to explore through the lens of evolutionary psychology and social learning theory, highlighting the diverse perspectives on human sexual behaviors.
Evolutionary psychology provides one explanation for these findings, suggesting...
Evolutionary psychology provides one explanation for these findings, suggesting...
01:28Causes of Social Behavior III: Biological and Environmental Influences
Social behavior is a complex phenomenon that arises from the interaction between biological predispositions and environmental influences. This intricate interplay shapes how individuals think, feel, and act in various social contexts. Understanding these mechanisms requires insights from psychology, neuroscience, genetics, and evolutionary theory.Environmental Influences on Social BehaviorEnvironmental factors, including temperature, odors, and visual stimuli, play a crucial role in shaping...
01:28Amebiasis
Entamoeba histolytica, a protozoan parasite, is responsible for intestinal and extraintestinal amebiasis. Though a significant proportion of infections remain asymptomatic, approximately 50 million individuals annually are estimated to present with clinical disease, resulting in up to 100,000 deaths globally. The disease burden is disproportionately high in regions with lower socioeconomic status, such as parts of India, Africa, Mexico, and Latin America.Etiology and TransmissionThe infective...