A higher rating generally indicates that in my opinion, assuming all other factors are equal, a colonist with this trait is more desirable to have in my colony.
Having played Rimworld for a fair amount of time and also because I feel like it, in this article I will rate all the traits available in the latest version 1.0 version of unmodded Rimworld while playing one of the preset scenarios with explanations for my ratings. Furthermore, specific situations may determine how useful or harmful the effects are. Traits can provide a wide variety of effects that are beneficial or detrimental, though often they have both. One aspect of the numerous details within the game are the traits that colonists may have up to three of. I especially enjoy the game for the numerous details that encourage strategic thinking, though new players may find themselves overwhelmed even after playing through the tutorial.
Rimworld is a game I've been playing on and off for about a year, often bingeing for days at a time before getting bored of the colony I'm managing and moving on.