Girl-power: Determines how often she will bathe and change her clothes. Also determines what she wear in appropriate situations. I.E. Jeans and a Flannel with a hat to go mining, a swimsuit to go fishing or wading in water, or pajamas when she goes to bed. My girl Melody has a high "Girl-power" and social, she is always fashionably changing her clothes (you must create/save multiple outfits in the creator), bathing, cooking meals, and creating her own social events with the other girls, inviting them over to her ruins mansion for coffee and dinner... She also often gifts me special food items with various status effect qualities.
Trust: How well she will respond to your suggestion and advances. Combined with a high darkness and perversion rating this leads to the series of "trust" events which unlock the hero subdued and restrained lines of h-positions. These are controlled by the female, you can speed up and slow down animations as well as select the normal finishes, and switch positions (but she may switch back, since she is being dominant), however you cannot change location or it will end the sequence. This also makes her related experience get 3x bonus.
Humanity: Will affect her responses when you catch her naked, bathing, using the bathroom, or masturbating as well as the depth of her communication with the hero and other women on the island. Her dialogue will change as well as she becomes self-aware and questions the world and her feelings for you and/or the other women.
Instinct: How effectively she will forage resources and add them to your storage chest. She will advance more rapidly in all technical skills, combined with a high "Girl-power" she will learn to cook better meals with extra effects and curative properties. This combined with a high social will also cause her to give you gifts often, help the other girls advance their skills, or help them when they are sick or faint. Basically, she becomes a second hero character the higher this goes. My girl Harmony rocks for this, I gave her all the best equipment the game would allow me to give her. She forages up tons of alloy and batteries and gifts me stat books/items and skill chips on a daily basis, sometimes multiple times a day.
Perversion: The girl's overall neediness and horniness. This affects how fast her desire for sex arises, how often she will accept your invitations for sex, how often she will peep on others in embarrassing situations, how frequently she will be found masturbating, and how often she will need your attention. With this trait up as well as Darkness, she will engage you vastly more often in dominant sexual attacks against the hero and night rapings while you sleep. Eventually she will disregard other girls around you and bang you right in front of them. This will also lead to higher trust it seems. She will also engage the other girls in sexual conversations, potentially develop homosexual tendencies (I think this is from development in darkness and a lack of attention from the hero), start masturbating with the other girls, and then potentially have lesbian interactions, although I have not had any threesome activities yet, I think my Athena will break through that soon if it's possible...
Vigilance: This increases by catching a girl in various embarrassing or lewd acts, as well as the hero failing to help her in need, or being intentionally mean in the social interactions. This will make her more aware and cautious when she performs lewd or embarrassing acts like using the bathroom, bathing, getting naked/changing, and/or masturbating/peeping when the hero is in close proximity. She will move further away and will cover up more quickly in response.
Social: This trait determines how often she will be social and interact with the hero and other women on the island. This is her overall friendliness and chattiness. This combined with a high trust and perversion makes a super clingy girl that is attached to your hip... My Chastity has this affliction, she's like a lost puppy, but cheers for me and applauds me whenever I find something or complete a task. I believe that is because she has a positive personality trait combined with the high social score. She also gets bonus experience during social interactions, I think it seems about 1.5x the norm.
Darkness: How kinky, bitchy, possessive, deviant, and dominating she will become. This unlocks new BDSM and anal play type positions in the H-scenes, like the various forced piledriver rimjob positions (forget the name but it's called something like "the dirty Sanchez," the hero subdued/restrained "Trust" play, golden shower play, bukkake desires, and homosexuality.
I am about 40 hours in and there is still new story coming from the girls as they transition and become more self-aware. Even after they reach 4-heart ratings and have several hundred points they still seem to continue to evolve and do random new stuff, so I have no idea how deep the rabbit hole is with this game.