Neatness goes with knowledge because when a sim works in a Class IV lab being very meticulous and keeping everything scrupulously clean is necessary just to stay alive.


Edit: Y'all disagreeing made me laugh. Seriously? Really tiny sneaky deadly things like Ebola, Variola, Marburg, and Lassa are handled in Class IV labs. In sim terms, that'd be the mysterious illness with realsickness installed.

Random, but with weighting towards parent's Primaries and Secondaries. It makes for some very interesting Sims....the Lazy Athlete, the Shy Romancer, the Tough Parent, the Very Serious Party Guest and so on. People can be complex and full of apparent contractions and so my Sims can be too..

I randomize all of mine, using the Random Sim Generator. Sometimes I'll over-ride it if I have a strong feeling about a sim's aspiration, but I generally just take it. If I went by wants I'd have 90% Knowledge sims, cause all my sims roll wants for skilling, even AFTER they get their aspiration. And I need some variety, otherwise it gets boring fast. Right now I tend to avoid Knowledge, Family and Pleasure - I'm burnt out on the first two, and still just can't connect with Pleasure sims. So the aspirations being random is important to my game.

I don't really have a system. I just choose what I feel fits my simmie.

I love randomness since it adds variety to the game.
I randomize aspirations using Hook's randomizer unless my sim screams a certain aspiration like Cole Morand, spending his time cleaning, playing chess and barely interacting with other sims including his parents (Knowledge) or Claudia Granville-Carver (Popularity). She's loves interacting with her relatives.
My sims have 1/9 chance of getting Family, Pleasure or Romance and 2/9 chances to get Fortune, Knowledge or Popularity as a primary. If they rolled "yes" for a secondary, then they have 1/13 chance of getting Grilled Cheese and 2/13 chances of getting any of the other aspiration.
Since I have a very loose intelligence system (gifted sims are set to "smart" with the Batbox), I'd like to revamp my randomizer so only gifted sims and educated average sims would get secondary aspiration. I'm still debating.

To add to the playful Knowledge "debate", I have at least two of them (Noah Marcotte and Ariane Granville-Carver) who failed to go to uni (they went in aspiration failure since they didn't have the required score to go to) because they'd rather play in the bath instead of autonomously study. They barely roll skilling wants so I go with it. Noah will take his mother's salon over while Ariane will be promoted to PO's owner. She's currently the town's mailwoman.

Strangely enough, considering that I've been playing for nearly 4 years, and that I love playing teens, I've not had a child age up to a teen yet! (I do usually play with aging off.) All my teens are made in CAS, or they're Maxis teens, or a few have been generated in-game. Since I've got far more teens than children, I've tended to leave my children as children so there will be someone for the other children to play with.

When I eventually do let them age up, I'm sure I'll choose an aspiration based on what I know about the child's personality. Julian Moltke's little sister Brigitte will be Knowledge -- she's left me in no doubt of that since the first day I played her (and she's the first child I played). She always does her homework, the first thing she asked for was a telescope, and she effortlessly got her grades up to A+ within days of starting school. I'm not quite so sure about her little brother Hans, but I think he might be Romance. He's extremely good looking (and knows it) and, despite trying, he's never done all that well at school. He's close to, and very much influenced by, his gay elder brother Julian, and (thanks to BO's version of the Childhood Crushes mod) he already has a little boyfriend in Hermes Hunter. For his part Hermes and his older sister Candy are very likely to follow their mother (and her boyfriends) into the Romance aspiration; it is the way of life that they're used to, and it probably appears to them to be extremely enjoyable.

When it comes to the pre-made children in our Veronaville (Beatrice and Benedick Monty, Hal and Desdemona Capp, Gabriella and Gallagher Newson, Bottom Summerdream and Tessa Ramirez), I have as yet very little idea, except that, for obvious Shakespearean reasons, I'd quite like Desdemona Capp to pair up with Othello Moore (another CAS child). In Shakespeare's play, Desdemona was entirely innocent of the adultery of which she was suspected, so perhaps I should make her Family rather than Romance, but young Othello is such a delightful little boy, I can't imagine him ever behaving a quarter as badly as his Shakespearean counterpart.

In any case, with my ultra-slow playstyle, I feel I ought to know my Sims well enough to make an informed decision for each of them. It's the least that they deserve.

I roll a dice for primary and secondary aspiration, when they grow up. I prefer to have sims with a secondary aspirations so their wants are a bit more varied. I rarely change their aspiration later in life, usually only if they are Pleasure sims because I don't always have the nerve to deal with them. Jeremy Whimpe changed from Pleasure to Family (I think, not sure) after his father died, which made a lot of sense to me, since he was left with his little sister, an accident with a townie only a couple of days before he was going to die. I think Jeremy just wants to take care of Samara and her mother Medea, since his parents and brother died. He's also connecting with his nieces and nephews now. Maybe he'll start a family of his own, maybe not.

Sometimes I reroll, because I'm not overly fond of Pleasure and Grilled Cheese sims. I used to reroll romance sims as well, but they have grown on me and are so easy to keep happy.

I have a system that limits my choices to 3 based on OTH, and from there I choose based on personality and/or hood balance.

I don't have particular system. Most of my kids have developed personalities till they grow into teen stage, so most of the time I know what aspiration to choose for them. There are sometimes when there is just a kid with bland personality. Such kids moslty grow into fortune sims and some of them grow into attention seeking bland sims (popularity).

I do not change aspirations when my sims show constant interest in something else besides their primary aspiration interests. Instead, I use secondary aspirations from Free time. I like to use Freud's aproach to personality development, which is in early phases of life. Later on, sims can choose to change, but they can hardly stray from the person they originaly developed into.

If I play a story that I set up, however, I have already predefined aspirations. But I long passed the story play.

Some of my Sims have definite ideas of their aspiration (for example, Deborah Goodie's peacemaking efforts were the only reason her parents didn't get divorced after they cheated on one another, and she was adamant that she was a Family Sim, so got her wish). Most Sims aren't so sure, so I look at their left-most want at the moment the aspiration dialogue box appears and pick something appropriate to that. For example:

Skilling wants -> Knowledge
Buying a MP3 player -> Fortune
Buying/using a games machine -> Pleasure
Buying a phone -> Popularity
Interact with a family member -> Family
Interact with a non-family teen -> Romance

I never give Grilled Cheese out as an initial primary aspiration, no matter how much a child loves grilled cheese, though it certainly can become a primary aspiration later in Sims' lives! Also, I used to assign Fortune to any Sim wanting any of the gadgets, but then I got way too many Fortune Sims...

Some wants make me consider multiple options (some are situation-based, like interacting with a nanny when the Sims is already good at cleaning - is that a desire for friendship (popularity) or to share cleaning tips with an expert (knowledge)? - and some are always ambiguous, like wanting to eat mac and cheese).

As far as I'm concerned, every personality is equally capable of being any aspiration, they will simply express their aspiration differently.

I've only recently gotten the Ultimate collection and hobbies are new to me (had Uni, Pets, OFB, and Seasons before), so I've not used those to base my decisions. I look at personality points - sims who are shy or mean don't get Popularity aspiration. I don't enjoy playing Romance sims, so I don't think I've ever chosen that for a growing up sim. Family is chosen sparingly, because I like to fulfill wishes, but don't want my town to grow too large due to too many offspring. I've never used Pleasure as a primary aspiration, because I've heard it's not that fleshed out. I wish I could see their teenage interests before choosing - it's said when I pick fortune, then they have 3 interest in money.

If I got to choose I'd probably pick family or knowledge for all my sims because those are my favorites. Or I'd go by personalities, and that would mean every aspiration would be too similar. I do want to have some shy popularity or romance sims, serious pleasure sims, mean family sims, etc.

So instead I randomize it when my sims become teens. I like how this results in some sims with surprising personality/aspiration combos. That being said, if my sim randomly rolls an aspiration that I feel really does not fit, I reserve the right to roll again, though I try not to do this often. I use the secondary aspiration option to give my sims another aspiration sometime in their teen or adult years if I had an aspiration in mind that they didn't roll, I observe behaviors that indicate another aspiration, or just to add some depth to a sim. I especially like giving romance sims a secondary aspiration because it indicates that they have certain traits of a romance sim (liking physical affection/romantic interactions, having grandiose dreams for life like becoming an artist, etc.) but that they aren't necessarily interested in a lifestyle of woohooing as many sims as possible. One of my favorite sims at the moment, Peony Bloom, is a romance sim with a family secondary, and she has no real desire to cheat on her husband. On the other hand, another sim in town, Kieran, is a romance sim who owns the local bar and compulsively woohoos with as many sim ladies as he can.

I like the variety I get between randomizing aspirations and purposefully choosing secondary aspirations, and it allows me to have some control over sims' aspirations as they age up but not enough that I shoot myself in the foot and make things less interesting to play out.