I have a theory I’d like to test.

Looks do matter: they always have and they always will. A person’s looks matter more the less we know about them. If we know nothing about a person, their looks are all we have to go on. Assuming we can see. And if a person is physically attractive, we’re more likely to assume they’re also more honest, reliable, hardworking, kind, generous and so on. It also takes longer to convince us otherwise.

Secondly, our society emphasises looks: how to be more attractive and how to deal with the illnesses that arise from the psychological torment of not being beautiful. Ads use beauty to sell products, on the premise that beauty is desirable. And generally they are correct. Beauty is desirable: God himself gave us beauty, the ability to appreciate it and to create it in art. (‘So strength first made a way; then beauty flowed, wisdom, honour, pleasure …’ [The Pulley by George Herbert])

But how we express that appreciation has limits. Telling a lady – I focus on the female of the species – she has beautiful eyes is acceptable. Telling her she has beautiful legs is getting close to the border. Telling her she has beautiful breasts is to cross the line. The reason being, I think, that eyes are innocuous; everyone has them. In western culture, when we’re talking to a person it’s polite to look them in the eye (part of the ‘social gaze’); and eyes don’t imply anything about our worth or nature or completeness. To compliment a person’s eyes is perceived as a thoughtful, flattering, perhaps even courteous, gesture. (Or, possibly, creepy, if the compliment comes from someone the recipient isn’t attracted to.)

Legs, though, are a part of us that can be improved by physical exercise and grooming, and they do have an appeal for both sexes. To compliment someone’s legs shows that you are looking at them with more than a social gaze: you are being more than disinterestedly courteous to them. It implies you have a deeper acquaintance with them that allows for a more personal comment.

At the other end of the scale, to compliment a woman’s breasts is to focus on her sexuality, rather than her intellect or character. She may have a rack that can lower interest rates, initiate the Apocalypse and reconcile everyone to the French – but you must never compliment her on her breasts unless you’re her partner or at a similar level of intimacy. To comment on an essentially sexual aspect of a person implies that you share the deepest type of relationship.

To paraphrase the old line, ‘It isn’t just what you do, it’s the way that you do it.’ How you compliment someone has an effect, too. ‘Nice tits’ is what she believes all men are thinking – but it’s vulgar for a guy to actually say so. ‘They’re magnificent!’ is only redeemed from vulgarity by three extra syllables but will still get you crossed off her Christmas card list, if indeed you’re aiming for something that long-term. ‘They’re magnificent!’ plus an explanation of how they are so marks you as a poser and a gourmand, on a slightly lower level than the vulgarian with his ‘nice tits’ comment. She already knows why they’re magnificent: they are hers after all.

So with all this background in place, my theory is that, if a person doesn’t know you, how they react to your compliment will be determined by how attractive you are to them. The more attractive you are, the more you can get away with. (See the first paragraph.) The actual test would be a questionnaire based on a three-by-three matrix of attractiveness by intimacy, like so:

The compliment table.

There will be, I’m guessing, a slight difference in how males and females react. Any compliment from a person perceived as unattractive by a male will be rated more negatively than it would by a female. The second aspect to this hypothesis is that females generally rate compliments more highly than males, irrespective of the complimenter’s perceived attractiveness. But generally, approval ratings will decrease with two factors: the less attractive the complimenter is perceived to be, and the more intimate the body part complimented.

There is also the aspect of how much the person can work on that part of their body – the more effort they have put in, the more positive they will feel about your compliment. For the purpose of this study, though, we will assume that the effect is negligible.

A final warning: don’t try this at home unless you’re a trained psychologist, extremely good-looking or highly agile (and thus able to avoid projectiles intended to cause damage).