Taking a scientifically neutral approach to sexual response, Kinsey often emphasizes tactile stimulation in sexual activity, as well as the important role that psychologic conditioning plays in determining our erotic triggers. This is especially true with regard to the question of homosexual experience. Whereas mainstream opinion (more so in the mid-twentieth century when his research was first published) was of the belief that most people are straight and a minority are "gay", Kinsey found that homosexual experience was a lot more prevalent than previously thought.
But further, in my interpretation, he seemed to be a proponent of the theory that the human organism could respond to a wide array of stimulation, not strictly limited to one's narrow preferences. For example, a true heterosexual male (with no feelings of homosexual attraction), might respond physically (if not psychologically) to the experience of another male tactilely stimulating his genitalia, so long as he keeps his eyes closed (or perhaps even otherwise). This is not necessarily a statement about his psychological preferences, but merely evidence of the physical aspect of sexual arousal.
Kinsey, however, almost seems to want to extrapolate this observation in an effort to suggest that a person's preferences are not so much hard-wired as being conditioned by one's experiences - after all, if a "straight" man can become physically aroused by homosexual stimulation, then the only thing keeping him straight is his psychological conditioning to believe that heterosexual contact is desirable and homosexual contact is not. While there may be some truth to this view, I don't think it adequately explains the full situation.
For example, in a world that shuns homosexual contact (again, much more so in the mid-twentieth century), how is it possible that a person could become conditioned to prefer - maybe even exclusively - such contact? It seems to fly in the face of the - fairly popular nowadays - "born this way" theory; and, simultaneously, dangerously lends credence to the belief that a person's sexual preferences can, ostensibly, be forcibly changed through re-conditioning (a theory that has had a less than stellar track record in practice).
While it is probably true that people are a lot more fluid in their sexualities than they often give themselves credit for, and I appreciate any attempt to encourage people to experiment with new possibilities (and be more compassionate and understanding of others not like them), I'm just not so sure that a person's preferences are not at least a little bit wired from the start.
Certainly, the particulars of my sexual tastes have evolved through the years, and it is hard to acknowledge an attraction to something you haven't really had the opportunity to be exposed to, or seriously considered in an erotic context, but I don't see myself as ever having had a drastic change of preference; and though I might come to see the maybe not-so-obvious appeals of alternative erotic triggers, I have a hard time believing that the basic, physical force behind my attraction to the things I like will ever change on a fundamental basis.
Maybe it's because the role of conditioning is far more potent during a person's formative (i.e., childhood) years, but even then, how do you explain the existence of people who seem to have preferences that go against the grain of their upbringing? I think this is a fascinating question to ask in the realm of sexology - what makes people like what they like - but I think there are still some important pieces of the puzzle missing.