Psychology
noun
The reason your heart does what it does is all psychological. The study of that is psychology.
しんりがく
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.
えいぎょうをするなら、心理学を学んだ方がいいよ。
You should study psychology if you work in sales.
心理学のせつ明によると「あい手にひどいことが言えるということは、その人にいぞんしてるということ」らしいです。
According to the psychology explanation, it looks like when you are able to say something mean to a person, you're actually being dependent on them.
私は大学で犯罪心理学を専攻していました。
My major was criminal psychology in college.