While in ordinary speech, the terms sex and gender are often used interchangeably, [1] [2] in contemporary academic literature, the terms often have distinct meanings, especially when referring to people. Sex generally refers to an organism's biological sex, while gender usually refers to either social roles typically associated with the sex of a person gender role or personal identification of one's own gender based on their own personal sense of it gender identity.
In most individuals, the various biological determinants of sex are congruent, and sex is consistent with the individual's gender identity, [14] but in rare circumstances, an individual's assigned sex and gender do not align, and the person may be transgender.
Though sex and gender have been used interchangeably at least as early as the fourteenth century, this usage was not common by the late s. The Oxford English Dictionary defines sex as "Either of the two main categories male and female into which humans and many other living things are divided on the basis of their reproductive functions;". Merriam-Webster defines sex as "either of the two major forms of individuals that occur in many species and that are distinguished respectively as female or male especially on the basis of their reproductive organs and structures.
They also note that "[d]octors can alter the physical characteristics of sex, but bodily sex does not determine gender. Anisogamy , or the size differences of gametes sex cells , is the defining feature of the two sexes. By definition, males are organisms that produce small, mobile gametes sperm ; while females are organisms that produce large and generally immobile gametes ova or eggs.
Bhargava et al. They state that "[s]ex is dichotomous, with sex determination in the fertilized zygote stemming from unequal expression of sex chromosomal genes. Other studies have noted that, while there is some tentative evidence for a potential genetic, neuroanatomical, and hormonal basis for gender identity, the specific biological mechanisms involved have not yet been demonstrated.
