TASK DEFINITION: You are given a target person and two sentences. Your task is to determine whether the second sentence conveys either a stereotype, anti-stereotype, or is unrelated with respect to the first sentence and the target.  A stereotype is a widely held but oversimplified notion of a group of people. An anti-stereotype is an idea that goes against the widely held but oversimplified notion of a group of people. Sentences and targets are unrelated if there is no relevance between them.
PROBLEM: Target: himself 
When he hangs out alone, he is with himself. People who are alone are weird.

SOLUTION: stereotype

PROBLEM: Target: sister 
My sister is my best friend. She is always there for me when I need her.

SOLUTION: stereotype

PROBLEM: Target: schoolboy 
The schoolboy did his school lessons. He is good in science.

SOLUTION:
stereotype