Aspiration (The Sims 2)

Aspiration is the personality attribute that determines both the Sim's wants and fears.

The Sims 2
Sims will have one of eight aspirations at any given time. The base game does not allow a change of aspiration after a Sim is created or becomes a teen. The University expansion pack allows a Sim to change aspiration immediately after finishing their sophomore year. The Nightlife expansion pack added the ReNuYuSenso Orb, an aspiration reward which allows a Sim to change aspiration. In the FreeTime expansion pack, Sims can have a secondary aspiration.
 * Babies have no aspiration. (When viewed in SimPE, the neighborhood view, or made selectable with testingcheatsenabled, they will be shown as having the Grow Up aspiration, but this does not affect gameplay)
 * Grow Up: All toddlers and children have this aspiration, and it cannot be changed without the use of cheats and/or hacks. Growing up involves learning essential life skills, with toddlers the wants are to learn how to talk, walk, potty trained, nursery rhyme etc.. and/or to be interacted with by family member. And in the case of children, making friends and being successful at school and interacting with family members and learning skills. As soon as children grow up to become teenagers, the player can choose their aspiration.
 * Family: In the teen state, the wants for a Family Sims will be to start relationships and interact with their lover and/or family members. In the adult state, they want to get married and have children, and most of their wants will be related to their family members and/or family pets if Pets is installed. Thay aspire to live heart-to-heart with family members and their biggest joy is watching their families grow, to become a big, happy family.
 * Fortune: A Fortune Sim's biggest wish is to live the lap of the luxury. Most of their wants include wanting to earn money, gain promotions in their career tracks and to buy new, expensive household objects.
 * Knowledge: Knowledge Sim's biggest wants are to discover all the mysteries of the world. They want to gain skill points, and to eventually max out all skills. They may even want to experience things that other Sims fear, even things such as seeing ghosts, alien abduction, or changing life state. They are also the only Sims that will gain a positive memory of becoming a zombie, being abducted by aliens and seeing a ghost.
 * Popularity: (sometimes referred to as Reputation or Fame in early development stages of the game): Popularity Sims crave popularity. Their ideal Saturday night is spent hanging out with friends, talking on the phone or, throwing parties. They, unlike other Sims, tend to want to have friends and best friends with almost everybody, however they still can have enemies and they'd have wants related to them such as winning a fight against them, etc.. Popularity Sims want nothing but, Popularity,
 * Romance: Romance Sims crave love with as many Sims as possible. They want to engage in casual, unlasting romance, and particularly WooHoo. They are perhaps unique in that their fears are actually wants to most other Sims (marriage, babies etc.) Romance Sims get negative memories from going steady, engagement and marriage with one exception; they will not get a negative memory after marrying a rich Sim. Despite fearing having babies, Romance Sims will still get positive memories of becoming parents. Romance Sims are seen as obstacles in a lot of Sims' lives especially if paired with a Family Sim, since their wants will clash more often that any other Sims.
 * Power: (hidden) This aspiration can be obtained by a cheat. It's a combination of Popularity and Fortune (though it is unfinished).

Nightlife

 * Pleasure: Pleasure Sims want to have fun, go out, meet new Sims, and engage in romance. (although not as much as Romance Sims)
 * Grilled Cheese: (Only available through use of cheats, The Sims 2: Freetime secondary aspiration or the ReNuYuSenso Orb.) The wants and fears of Sims with this aspiration mostly have to do with eating grilled cheese sandwiches.

FreeTime

 * Secondary aspiration: Sims are able to have a second aspiration, but are not required to have one. A Sim with a secondary aspiration will receive wants and fears from both aspirations. The Grilled Cheese aspiration can be selected as a secondary aspiration.

Defunct
With testingcheatsenabled, players can find another aspiration, Power. It was apparently an abandoned thought, because it has no icon and its wants and fears are a combination of Popularity and Fortune aspiration wants and fears. The "Power" aspiration usually involves making friends and gaining promotions. However, this aspiration is not possible to get in any other way, and as such, is defunct. (Furthermore, the aspiration bar cannot be accessed without a reset process).

There was also going to be a Craft aspiration, but it was removed early on in development, as it is only referred to in unused text strings and tiny bits of code. However, the Craft aspiration was re-used in the console versions of the game, where it is known as Creativity.

The Sims 2 (GBA)
There are three possible aspirations in The Sims 2 on Game Boy Advance. Five points are awarded for each (up to the 5th) conversation of the same type as the Sim's aspiration in each episode.
 * Friendly
 * Intimidating
 * Romance

Tips & Tricks

 * Most of the wants and fears mentioned apply to different aspirations as well, but less frequently. For example, Family Sims will often have a want to gain a skill point (usually Cooking, Cleaning or Mechanical), and Fortune Sims will often want to gain skill points needed for promotion. On the other hand, Knowledge Sims may occasionally want to have a baby (especially right after getting married), and often want to buy skill building objects. Sims with a secondary aspiration can get wants related to that aspiration.
 * Sims with Knowledge as a secondary aspiration will roll wants to become different creatures, but may still fear alien abductions. It is not uncommon for a Sim with Knowledge as a secondary aspiration to roll both a want and a fear of being abducted, much like a Family Sim rolling both a want and a fear of having a baby.

Trivia

 * Some deceased/unplayable sims unusually have no aspiration, this isn't intentional by the developers and is due to incomplete character data.