Recently, I’ve been thinking about something that seems to happen to a lot of people: you become especially invested in a friend or a colleague—help them once or twice. They’re incredibly grateful at first, but slowly, your efforts start to become, in their eyes, something like “what you’re supposed to do.” One time you can’t help, and instead you get blamed—sometimes even told that you’ve changed. I’ve also stepped into this trap myself. For a while, I kept trying to be an “all-around good person,” only to realize that gratitude was decreasing while expectations kept rising.

Later, I finally understood that this isn’t because of human cold-heartedness, but because of a psychological principle called the “Weber’s law.” Put simply, the brain gradually “desensitizes” to repeated stimuli. At the beginning, your goodwill can move people. But as it happens more and more, the other person’s reactions become increasingly flat—even something they start taking for granted.

For example, receiving a gift for the first time makes you happy. The second time can still move you. But if it happens every day, you feel like it’s nothing special. From the perspective of neuroscience, it’s even more interesting—at first, benevolent actions release a large amount of dopamine, which makes people excited and happy. But the brain quickly learns to predict that this “good thing” will happen, so when it actually does, it’s no longer as stimulating. That’s also why the honeymoon phase always passes: after that, when you do the same things, the feeling isn’t as strong. In economics, this phenomenon is called “diminishing marginal utility”—the more you put in, the less fresh the return feels.

Psychologist Weber conducted a classic experiment involving people holding weights. When it increased from 400 grams to 405 grams, most people could feel it was heavier. But if you start with 4,000 grams and only add 5 grams, almost no one can tell the difference. It turns into a threshold game: the stronger and more frequent the stimulus, the lower your ability to distinguish. This “Weber’s law” doesn’t only apply to physical sensations—it also holds true in interpersonal relationships, consumer psychology, and even habit formation.

In 2016, an experiment from a UK psychology magazine was also quite interesting. It had participants receive different quantities of small favors every day, and the results showed that for everyone, the novelty of rewards at high frequencies disappeared quickly. Instead, after reducing the reward frequency, people valued them more and remembered them more deeply. Sometimes, less really is more.

So how do you reverse this “marginal effect of giving”? First, deliberately control the frequency of your giving, so that kindness becomes a bit scarce. Don’t go all in from the start—especially in newly formed relationships. Low-frequency but high-quality friendliness and help are much more likely to be appreciated than being available every day. When friends ask you for help, taking the initiative occasionally—or saying, “This time isn’t very convenient, but I’ll do my best next time”—can actually help them feel that sense of anticipation again.

Second, create small changes to increase unpredictability. The brain loves the element of surprise. It’s not about mechanically repeating the same kind actions, but about periodically switching up the approach and expressing care in different ways. This is especially effective in relationship management, team motivation, and even in family and parent-child interactions. Most importantly, keep your boundaries elegantly and learn to refuse in moderation. Every act of goodwill should make the other person understand it isn’t something easy or effortless. Setting boundaries is essentially about maintaining the “psychological threshold” of your emotions. Even just occasionally saying “no” can keep interactions fresh and respectful.

In the end, the core of Weber’s law is a reminder: don’t let your sense of self-worth depend entirely on other people’s feedback. Top performers don’t use this rule to manipulate others. Instead, they learn to adjust their sensitivity—choosing where and when to give with intention, and directing kindness to the people and matters that truly deserve it. If you treat good intentions like “hard currency” that gets discounted every day, in the end it will only be devalued.

If you can apply Weber’s law to self-awareness, every act of proactive kindness will feel more weighty. Carefully manage your giving threshold—be sensitive when you should be, and be less responsive when you should be. No matter how others respond, they won’t make you lose control of your initiative in relationships. Sometimes, this kind of psychological self-management works better than any interpersonal technique. Lately, I’ve also been paying attention to some related market dynamics on Gate, and it feels like many aspects of investment psychology follow similar rules.