Reference Terms
from Wikipedia, the free encyclopedia
Homosexuality
Homosexuality can refer to both attraction or sexual behavior between people of the same sex, or to a sexual orientation. When describing the latter, it refers to enduring sexual and romantic attraction towards those of the same sex, but not necessarily to sexual behavior. Homosexuality is contrasted with heterosexuality, bisexuality and asexuality.
Lesbian denotes a homosexual woman.
Most scientist today agree that sexual orientation is most likely the result of a complex interaction of environmental, cognitive and biological factors. Although homosexuality does not appear to be adaptive from an evolutionary standpoint, because homosexual sex does not produce children, there is evidence of its existence through human history.
Although a number of biological factors have been considered by scientists, such as prenatal hormones, chromosomes, polygenetic effects, brain structure and viral influences, no scientific consensus exists as to how biology influences sexual orientation.
Most scientists agree that it is unlikely that there is a single "gay gene" that determines something as complex as sexual orientation, and that it is more likely to be the result of an interaction of genetic, biological and environmental/cultural factors.
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January 18, 2026
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Jan. 15, 2026 Spikes in blood sugar after eating may be more dangerous for the brain than previously thought. In a massive genetic study, people with higher post-meal blood sugar had a much greater risk of Alzheimer’s disease. The effect couldn’t be explained ...
Jan. 14, 2026 A massive international brain study has revealed that memory decline with age isn’t driven by a single brain region or gene, but by widespread structural changes across the brain that build up over time. Analyzing thousands of MRI scans and memory ...
Jan. 13, 2026 Despite longstanding guidelines, many dementia patients are still prescribed brain-altering medications that can raise the risk of falls and confusion. A new study shows that while prescribing has decreased overall, people with cognitive impairment ...
Jan. 12, 2026 Researchers have discovered a brain activity pattern that can predict which people with mild cognitive impairment are likely to develop Alzheimer’s disease. Using a noninvasive brain scanning technique and a custom analysis tool, they detected ...
Jan. 8, 2026 A large review of studies suggests that exercise can ease depression about as effectively as psychological therapy. Compared with antidepressants, exercise showed similar benefits, though the evidence was less certain. Researchers found that light ...
Jan. 7, 2026 Teens who sleep in on weekends may be giving their mental health a boost. A new study found that young people who made up for lost weekday sleep had a significantly lower risk of depression. While consistent sleep is still best, weekend catch-up ...
Jan. 6, 2026 A familiar mouth bacterium best known for causing cavities may also be quietly influencing the brain. Scientists found that when this microbe settles in the gut, it produces compounds that can travel through the bloodstream and harm neurons involved ...
Jan. 6, 2026 Many people with multiple sclerosis struggle with balance and coordination, and this study uncovers a hidden reason why. Researchers found that inflammation in the brain disrupts the energy supply of vital movement-controlling neurons. As their ...
Jan. 5, 2026 A long-running debate over Tamiflu’s safety in children may finally be settled. Researchers found that influenza, not the antiviral medication, was linked to serious neuropsychiatric events like seizures and hallucinations. Even more striking, ...
Jan. 5, 2026 Nearly all women in STEM graduate programs report feeling like impostors, despite strong evidence of success. This mindset leads many to dismiss their achievements as luck and fear being “found out.” Research links impostorism to worse mental ...
Latest Headlines
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Jan. 16, 2026 Scientists have discovered that the adolescent brain does more than prune old connections. During the teen years, it actively builds dense new clusters of synapses in specific parts of neurons. These ...
Jan. 14, 2026 A new study reveals that alpha brain waves help the brain decide what belongs to your body. Faster rhythms allow the brain to match sight and touch more precisely, strengthening the feeling that a ...
Jan. 12, 2026 Waiting to eat when your food arrives first feels polite—but it may be mostly for your own peace of mind. Researchers found people feel far more uncomfortable breaking the “wait until everyone is ...
Jan. 12, 2026 A small group of people experience no pleasure from music despite normal hearing and intact emotions. Brain imaging reveals that their auditory and reward systems fail to properly communicate, ...
Jan. 11, 2026 A large genetic screen has revealed how stem cells transform into brain cells, exposing hundreds of genes that make this process possible. Among the discoveries is PEDS1, a gene now linked to a ...
Jan. 8, 2026 Exercise doesn’t just challenge the body; it challenges how the brain interprets effort. Scientists discovered that vibrating tendons before cycling allowed people to push harder without feeling ...
Jan. 7, 2026 Researchers in Japan built a miniature human brain circuit using fused stem-cell–derived organoids, allowing them to watch the thalamus and cortex interact in real time. They found that the ...
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Jan. 4, 2026 Researchers compared a traditional Chinese medicine, Yueju Pill, with a standard antidepressant and found both reduced depression symptoms. However, only Yueju Pill increased a brain-supporting ...
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