You must dig into the code, as suggested by d.stu: open the traits.gd file, find the effects and look for them inside the ".gd" files.
For instance the effect of "Pretty voice" is "pretty_voice": since no .gd script mentions it, the trait is still not implemented (most likely).
If you open "jobs&specs.gd" instead, under "storewimborn(person)" you will read:
if person.race.find("Tanuki")>=0:
bonus = bonus + 0.3
supplyprice += 1
which means that a Tanuki, when working at the Winborn market, earns more gold (+30%) and sells supplies at a higher price (?).