That Choice of Lifestyle

It is a lifestyle choice, built around a set of behaviors and practices. As such it is a self-constructed "identity."

There is no evidence that it is genetic or biological in origin, and it appears to be almost entirely due to nurture rather than nature. The fact that it may run in families is a result of context, not biology.

Because their behavior is not inherited and does not arise spontaneously, they have to recruit to maintain their existence, and are particularly focused on the young, the elderly, and the economically vulnerable.

It causes dissension and division in families, undermines the good order of society, and has been the cause of societal collapse. Nearly every past fallen civilization was riddled with this practice.

It has often been criminalized or otherwise discouraged or controlled by many governments.

In spite of efforts to suppress it, it often flourishes in a shadowy, underground world on the edges of society. They communicate with each other with symbols and code language, forms of dress, or mannerisms. They gather regularly in groups to share in its practice.
 

Some are bold enough to flaunt the behavior in public.
 

In spite of it being a self-generated identity based on entirely optional personal behaviors, they insist it be granted special protection as a "right" and even portray it as a "natural" right.
 

Many of them are active in the media and entertainment industry, and exercise disproportionate influence on the culture.
 

They form a particularly powerful "special interest group" and lobby extensively in support of their "agenda." Once they achieve a degree of power they usually become intolerant of all who disagree with them.

In case you haven't guessed by now, it is religion.

Tobias Stanislas Haller BSG 

in a satirical vein