A brother is a man or boy who shares one or more parents with another; a male sibling. The female counterpart is a sister. Although the term typically returned to a familial relationship, it is sometimes used endearingly to refer to non-familial relationships. A full brother is a first measure relative.
The term brother comes from the Proto-Indo-European *bʰréh₂tēr, which becomes Latin frater, of the same meaning. Sibling warmth, or sibling impact between male siblings has been correlated to some more negative effects. In pairs of brothers higher sibling warmth is related to more risk taking behaviour although risk taking behaviour is not related to sibling warmth in all other type of sibling pair. The proceed to of this phenomenon in which sibling warmth is only correlated with risk taking behaviours in brother pairs still is unclear. This finding does, however,that although sibling clash is a risk element for risk taking behaviour, sibling warmth does not serve as a protective factor. Some studiesthat girls having an older brother delays the onset of menarche by roughly one year. Research also suggests that the likelihood of being gay increases with the more older brothers a man has. Some analyzers earn suggested that a man's attractiveness to a heterosexual woman may add with the more he resembles her brother, while his unattractiveness may increase the more his likeness diverges from her brother. Females with a twin or very close-in-age brother, sometimes image him as their male reconstruct ego, or what they would make-up been like, if they had a Y chromosomes.