An interesting article in National Geographic shows current research suggests they have consistent personality traits and that the traits can be inherited:
‘Lemurs have identifiable personality traits that are consistent from situation to situation, and those tendencies may have evolutionary implications, according to a new study conducted at the Duke Lemur Center.
Ecologist Jennifer Verdolin tested captive gray mouse lemurs, small, large-eyed primates native to Madagascar’s forests, to see how they reacted to unfamiliar objects and foods.
She placed items such as a tiny chair, a wooden ladybug, and a stuffed toy frog, as well as new foods such as mango and papaya, into the animals’ enclosures. After classifying individual lemurs’ reactions, she monitored how agitated they became during routine handling for cage cleaning and health measurements.
Bolder lemurs-those who spent more time interacting with the new objects-were less likely to urinate, defecate, bite, or otherwise protest when handled, compared with their counterparts who had avoided the unfamiliar objects. (The study didn’t find a measurable difference in their reactions to the new foods, perhaps a sign that the lemurs did not perceive them as unusual.)
Verdolin explained that these protest reactions likely reflect fear, and that the bolder lemurs responded with more confidence in the stressful situations. Bold lemurs may be more likely than shy ones to adapt to uncertain or changing environmental conditions, and boldness and shyness may run in families.
“There’s actually evidence of heritability in these traits,” Verdolin explained, which would have implications for the evolution of the species.”