Straight (= heterosexual)
As early as the sixteenth century "straight" had come to mean honest, as in business dealings. By 1868 a sexual (or rather nonsexual) meaning had emerged: a straight woman was a chaste one. This development produced a template contrasting “good women” (who preserve their chastity) and "loose" or "fast" ones. And this template underlies the pairs -- straight: heterosexual :: bent: gay.
What is the origin of the assumption that, in effect, it is always best to follow the shortest route between two points? The trope seems to be cross-cultural, as seen in the Latin word rectitudo, reflecting recta via, on the right (straight) path, and yielding our "rectitude." In its English versions the Bible often praises "righteousness," echoing the Hebrew sedek. A straight path is one that goes in the right direction (cf. Psalm 23:3).
There is some non-Western evidence as well. In the Analects Confucius warns against "twisted thoughts."
Cross-cultural it may be, but the contrast between straight = good and detour = bad is not a semantic universal. The French lesbian theorist Monique Wittig lived in the United States for a number of years. In 1992 she brought out a book The Straight Mind. When she decided to translate it into French the title read "La pensée straight." Apparently she was unable to find an exact equivalent in French for this expression, so familiar in English. Similarly, in German the adjective "gerade" seems to lack the secondary connotations of the English "straight."
Not surprisingly, American gays have reacted against the value judgment implicit in the contrast of straight and gay. During the 1970s and 80s the independent editor Boyd McDonald published an underground magazine in New York City originally entitled Straight to Hell (aka S.T.H., The Manhattan Review of Unnatural Acts). Nowadays, some gay reactions against the usage seem to go too far, as the T-shirt some men wear that reads "I can’t even think straight'" It is one thing to note and deplore homophobic slurs; another to adopt them as one’s self-definition.
The expression "get straight" suggests that the condition of nonstraightness can be overcome. This may be the case with emerging from a state of mild confusion or a period of indulgence in drugs, but most gay people believe that with regard to sexual orientation it is not such a simple matter. At the other extreme of the spectrum, those who disparage homosexuality is a deplorable character stain do not accept that it is easy to expunge.
Since heterosexuals tend to assume that (absent contrary evidence) everyone has the same orientation they do, they have little use for the term straight. Still, there are indications of a fledgling Straight Pride Movement. Or so a prowl on the Internet suggests. How serious this trend is remains to be seen.
All this being said, how boring is this notion that one may never wander from the most direct route! And how fascinating and rewarding bypaths can be!
Moreover, the ideal of perpetually remaining straight does not reflect a realistic assessment of human nature. This approach is not simply boring, it is almost impossible to maintain. In a saying embraced by Isaiah Berlin, the philosopher Immanuel Kant noted "Out of the crooked timber of humanity, no straight thing will ever be made."
Finally, what is the purpose of the current Internet rendering "str8"? Cute it may be, but it is paradoxical also, because in our mathematical notation the symbol for eight , with its crisscross intersection of the single curved line, is hardly an exemplary rendering of the concept of straight. Even staid Euclidean geometry admits curved lines; otherwise why bother with calculating the value of pi? Piet Mondrian was one of the very few artists not to employ curved lines
Placed on its side [∞], the figure 8 means infinity. Perhaps that is fitting enough, for it seems that this dialogue between moral straightness and its more realistic competitor, allowing openness to deviation, will never end.