That's a way in which the article is deliberately misleading. Inheritance is just one way in which wealth is transferred intergenerationally. By highlighting the small percentage, the article creates a false impression that a significant amount wealth is bootstrapped by individuals.

That got me thinking about the obvious question - how are they counting people who married into wealth? They have 23% getting wealth from employment, 16% from inheritance, and 43% from owning a business. That only leaves 14% for spouses (less lottery winners, malpractice award recipients, etc.) That just doesn't seem correct - considering the frequency of marriage among adults.