Interest

A Sim's interests are randomly generated when the Sim is created or born in The Sims and The Sims 2. The more points in an interest, the more interested a Sim is in the particular subject. The interests that a Sim has the most points in are the ones they will usually talk about when they initiate a conversation, or be interested in when being talked to. For the most lengthy and constructive conversations, it's best to talk to Sims that have similar interests. Specific interests can be increased by reading magazines, but increasing certain interests will force other interests to decrease.

The Sims
In the original release of The Sims, there were 8 interests; Travel, Money, Politics, 60's, Weather, Sports, Music, and Outdoors. For children, the first four were replaced by Toys, Aliens, Pets, and School. The Hot Date expansion pack added 7 more interests that were only available to adults; Exercise, Food, Parties, Style, Hollywood, Technology, and Romance. Hot Date also introduced magazines, which adult Sims can read to change their interests. Gaining an interest point in one subject will cause the Sim to lose an interest point in another.

Interests run on a 10-point scale, from 0 to 10.00. If a Sim has between 0 and 3.0 points in an interest, he or she will react negatively to it, and will lose relationship points with the speaker. He or she is likely to end the conversation, but may just change the subject. Either way, the thought bubble for the interest will have a red X through it. If a Sim has between 3.01 and 6.0 points, he or she will react positively enough to continue the conversation and gain relationship points with the speaker, but is likely to change the subject. The thought bubble for the interest will still have a red X through it. If the Sim has at least 6.01 points in an interest, he or she will react positively, and the thought bubble will not have a red X.

All interests that the Sim has at least 6.01 points in will appear when the player uses the Change Topic interaction. Only adults can use the Change Topic interaction, and they can only use it when they're involved in a group activity. It's not available when two Sims are just talking to one another, whether face-to-face or on the phone.

Interests and Maxis-made Sims
In general, Maxis-made Sims have one or two strong interests, and little or no interest in other topics. Taking these Sims to a community lot seems to "unlock" them, so that they will have a full range of interests. Old Town is useful for this, as going there is a family affair, and is free.

The Sims 2
There are 18 interests, and they're the same for all ages. The interests are Paranormal, Sci-Fi, Health, Politics, Culture, Environment, Food, Travel, Weather, Crime, Money, Work, Entertainment, Fashion, Sports, Animals, School, and Toys. A controllable Sim's interests can be found on the Simology panel.

Interests run on a 10-point scale. In general, Sims with at least four points in an interest will react positively to it. Kids can use the Change Topic interaction, and it is available when Sims are just chatting with one another, as well as in group activities. When using the Change Topic interaction, the player will be able to choose any interest, regardless of how many points the Sim has in it.

Interests can be changed by reading magazines or through the "Share Interests" social interaction.

Interests are unlike personality points. It is impossible to have 10 in every single interest because once an interest is increased by one point another one will decrease by 1 point.

In The Sims 2: FreeTime, interests are affected by gaining or losing enthusiasm in certain hobbies. Interest change corresponds to the enthusiasm gain or lose.