Big list of simple traits

[Goryus]

Vegetarian - gets a mood buff from eating vegetables, and a mood debuff from eating meat.
Carnivore - gets a mood buff from eating meat, and a mood debuff from eating vegetables.
Platonic - isn't interested in romance.
Shy - doesn't converse with others much.
Talkative - converses with others very frequently.
Unfaithful - more likely to engage in affairs when in a relationship.
Devoted - unlikely to engage in affairs when in a relationship.  Has a higher than average social opinion of their partner.
Perverse - finds disfigured people attractive.
Nyctophobe - Gets a mood debuff whenever they're in the dark.
Workhorse - Can carry more than the average load.
Lightweight - Can't carry as many objects in a stack.
Tough - gets reduced mood debuffs from experiencing pain.
Wimp - gets heightened mood debuffs from experiencing pain.
Polygamous - is willing to start a relationship with someone who is already in one.
Sleepy - has a reduced consciousness value.
Traitorous - may one day betray you and become hostile.
Art Lover - will only find Joy in viewing art.
Couch Potato - will only find Joy in watching TV.
Pool Shark - will only find Joy at a Billiards Table.
Gamer - will only find Joy at a Chess board.
Fixer - Gets a mood debuff if your colony contains any broken down equipment.  Gets a mood buff whenever he fixes something that broke down.
Planner - gets a big mood debuff, but becomes happier and happier the more of the research tree you've completed.
Miser - gets a big mood debuff, but becomes happier and happier the more wealth your colony accumulates.
Populist - gets a big mood debuff, but becomes happier and happier the larger your colony's population becomes.
Clean freak - hates being in a dirty environment.  Will drop whatever they're doing and start cleaning if they see dirt.
Homesick - gets a mood debuff whenever outside of the "home" area.
Promiscuous - does not have to be in a relationship to get Lovin'.
Hunter - gets an accuracy bonus while hunting.
High metabolism - food bar empties more quickly, requiring more meals to stay happy.  Gets an efficiency boost.
Hummer - likes to hum a lot.  Makes other people dislike him slightly.
Amiable - won't start social fights.
Hat lover - isn't happy unless he's wearing a hat.
Bisexual - is romantically attracted to both genders.
Sweet tooth - gets a mood debuff, but gets a large mood buff from eating Chocolate and Insect Jelly.
Cremator - wants to be cremated when they die, and makes this known.  Other colonists get a mood debuff is this colonist is buried.
Salesman - gets better discounts when negotiating with merchants.
Gullible - gets charged extra by merchants.
Persuasive - better at convincing prospective colonists to join you.
Bumbling - sometimes drops items they are holding.
Obsessive - when they join your colony, one random colonist is selected as their "crush."  They have a very high social opinion of that colonist and are extremely attracted to him/her.
Artillerist - better at manning mortars than your average colonist.  Reduces the shot time and improves accuracy somewhat.
Fashionista - loves tailoring clothes.  Gets a mood debuff if not assigned to tailoring.
Swimmer - can walk through water / marshy areas.
Expensive tastes - gets a mood debuff if their bed isn't made from a rare material.
Claustrophobic - gets a more severe mood debuff when feeling cramped.
Paranoid - unless wearing a tinfoil hat, gets a large mood debuff when near a Comms Console or an Orbital Trade Beacon.
Committed - more likely to make and/or accept marriage proposals.
Philosophical - more likely to engage in Deep Talk with other colonists.
Superficial - less likely to engage in Deep Talk with other colonists.
Friendly - seems to have a high opinion of everyone.
Suspicious - seems to have a low opinion of everyone.
Deaf - hearing stat is reduced.  Isn't bothered by "Creepy Breathing," "Annoying Voice," or "Hummer."
Outdoorsman - gets a mood debuff from being indoors, and a mood buff from being outdoors.

List of simple usability improvements is here:
https://ludeon.com/forums/index.php?topic=27327.0

[haywire-2014]

Yes, Tynan please add these!!!!

[schizmo]

"Sweet Tooth" sounds like it could easily be treated the same as drug addiction, with a declining "sweet tooth" meter resulting in a cranky colonist who is suffering from chocolate withdrawal. The only problem is chocolate is far too uncommon so sweet tooth would effectively be a debuff.

[CortexVortex08]

The majority of these are horrible. Do not want.

[jmababa]

I like these add it in A16