Recently, I’ve been pondering a question: why are we always so easily trapped by human weaknesses? Actually, there are many interesting patterns hidden in human psychology. If you can understand these, you’ll see through many people and events clearly.

First, let’s talk about the sunk cost fallacy. I’ve seen too many people fall for this. Some know that a relationship has problems, but they just can’t bring themselves to leave, not because they love the other person more, but because they’ve already invested too much. The more you’ve invested, the harder it is to let go. This psychology is the same in investments and job choices— the bigger the investment, the harder it is to abandon, even if you realize it might be a mistake.

Next, look at Murphy’s Law: the more you worry that something bad will happen, the more likely it is to actually happen. This isn’t some mysterious power; it’s because your attention becomes overly focused, making you especially sensitive to related signals.

There’s also a very practical concept in human psychology called the face-saving effect. If you first make a large request and get rejected, then make a smaller request, the other person is usually reluctant to refuse again. This is driven by the desire to maintain consistency.

Interestingly, there’s the inverse proportional law: when you don’t cherish someone, they tend to cherish you the most. But once you start showing kindness proactively, you’re more likely to be looked down upon. The curiosity effect is similar—maintaining a bit of mystery and distance can actually arouse others’ interest. Constantly flattering with humility only breeds dislike.

The broken window effect is everywhere in daily life. A clean place makes people hesitant to litter. But once the first piece of trash appears, countless others follow. Small issues, if not stopped early, can create a trend that’s hard to reverse once it takes hold.

The foot-in-the-door effect is also crucial: once someone agrees to your small request, they’re more likely to agree to a bigger one. That’s why sales often start with small orders.

The cage effect states that the more you possess, the less satisfied you are. Buy a pair of shoes, and you want a matching outfit. The more you own, the more your desires grow. Conversely, the forbidden fruit effect suggests that the more you want to hide something, the more others become curious. For example, if someone tries to hide their receding hairline, it often draws more attention.

In human psychology, there’s also the Rosenthal effect: if you’re introverted, the best way to change is to label yourself as extroverted during your first self-introduction. Behavior is guided by consciousness; if you believe you are a certain way, you will gradually become that way.

The Pandora’s box effect describes reverse psychology: the more you try to hide something from me, the more I want to see it. Franklin’s effect states that people you’ve helped may not repay you, but those you’ve helped before are often willing to help you again.

The cup effect is useful in dating. If you’re sharing a drink with someone, gradually bringing the cups closer during conversation indicates interest. If they don’t react, it shows they like you. If they move their cup away, they’re guarded. The suspension bridge effect is similar—taking someone you like to a special place and telling them it’s your secret base can quickly deepen your bond.

The recency effect is interesting: in a group report, the last person to speak is often the most convincing. That’s why leaders tend to speak last. The generation effect states that learning by doing is much faster than just studying existing knowledge.

The peak-end rule might be the cruelest: if someone does 99 good deeds, just one bad act can brand them as a bad person. Conversely, 99 bad deeds and one good one can turn things around.

The hippocampal effect explains that feeling of familiarity—your brain is recalling a movie or novel you’ve seen before. The sour grapes effect reveals that the more insecure someone is, the more they want to see others fail. Those who flatter the strong tend to be irritable toward the weak. People who are unsuccessful outside often become domineering at home.

These patterns in human psychology are essentially telling us to be cautious of others. It’s not about being suspicious, but about understanding these weaknesses and patterns so you can better protect yourself and view others more rationally.