A 20-year tracking study at Harvard found that only 4% of people are able to accumulate more than 96% of the wealth. The key factor behind this gap is not IQ, emotional intelligence, or social connections, but a capability that many have never noticed—"time horizon."

Time horizon refers to how far into the future a person can see when making decisions. Harvard professor Banfield pointed out that a person's social and economic status is significantly positively correlated with the length of time they consider into the future.

Stanford University's famous "marshmallow experiment" also showed that children who could resist eating the marshmallow immediately were more likely to achieve success as adults. The reason behind this is that the brain's prefrontal cortex (responsible for rationality) can suppress the limbic system (responsible for desires), enabling people to make choices with long-term value.