Jamaica is an island of contrasts, from the extreme por to the obscenely rich, from the sterotypical jolly "no problem" attitude, to a vicious inlerance of differences. jamaica is a very, very different island to the rest of the Caribbean. There is a huge "us-them" culture in Jamaica. My family come from the south central part of Jamaica and when my grandparents return, people treat them as if they are aliens.
It is very easy to get into an arguement with a Jamaican as they often seem very opinionated and caustically sarcastic to British/American ears.
I recommend to stay in the Northern, more touristic part of the island, Ocho Rios, Dunn's River, Negril, Montego Bay etc... They are very beautiful. You will find many "natives" who are very friendly as well as European and American tourists.
The South part of the island is more poverty-stricken and crime-ridden, particularly Kingston. When i was in Kingston for one day, i heard two gunshots and was terrified. Being from England, i'd never heard a gunshot in my life. Be careful not to wander around on your own always travel with a party or with a guide. The rest of the south part of the island has very nice friendly people, but you have to be careful because there is a lot of theft due in part to the poverty. Keep digital cameras and camcorders well hidden.
Be very careful that they don't overcharge you, because, as with anywhere, they can tell you are a foreigner and will often charge you 10-fold the original asking price.
Many Jamaican men display behavior and attitudes that might shock visiting women, often expressing disdain for the notion of female equality or women's rights. Rape is rampant in Jamaica. If you're a single woman, it will be assumed that you're on the island searching for a 'fling' Any argueing to the contrary will likely be met with tiring attempts to get you to change your mind.
If you go along with the flirting, don't expect a Jamaican man to understand if you've no intention of going all the way. Your innocent acceptance will be taken as a sign of acquiescence. The Jamaican male has a fragile ego and is likely to react strongly to feeling like a fool. Be clear about what you want.
If you are gay, DO NOT under any circumstances reveal that information. Jamaica is one of the MOST adamantly homophobic nations in the WORLD. Don't expect to be able to display your sexuality openly without an adverse reaction. Beatings, murders, torture and slashings of gays (or those suspected of being gay) are not uncommon, among both the police and civilians. If the police are called, they will often just sit back, watch and laugh, or even join in the beating.
It sounds quite negative but these are just guidelines of things to be careful of. Its a lovely island, really, if you know what you're doing.