Most of these are pretty true for research mentors at all levels.
1. If I don’t hang out and chat at the lab, it doesn’t mean that I don’t like you.
It probably means that I’m overextended or don’t have much spare time each day. I might be in the lab more hours per day than you are in an entire week, and I still might not have enough time to accomplish my goals. Alternatively, your lab schedule might overlap with my busiest time of the day, or I might need to leave lab at a specific time each day, leaving me no extra time to socialize. Therefore, I might focus on conversations that teach you how to interpret results or gain a new research skill, because I want our limited time together to make the greatest impact on your research experience. That might mean sticking to conversations about research and science.