Gordon Allport was a really smart guy who studied how people think, behave and feel. He thought about why people have different personalities and came up with some ideas that we can understand.
So, you know how some people are shy and quiet while others are really outgoing and talkative? Allport said that these differences come from our genes, our experiences, and our environment - which is where we live and what we do every day.
He also said that our personality changes over time, and that we have different levels of personality traits. This means that some traits are more important to us than others, and they show up in everything we do.
Overall, Gordon Allport helped us understand why people are different, and how our personalities shape everything we do.