Aigis' initial personality is simply a robot designed to obey orders. As a result of having no emotions, Aigis' social skills are more or less nonexistent; it's frequently noted that while she may look human, she is far from passing as such. She is prone to doing very strange and socially unacceptable things. Though over time she learns to become a bit more expressive and cheery.

Voice Reference: https://www.youtube.com/watch?v=tg38wkp9bzs&ab_channel=SwagotoYuki