First, what does it mean to be smart; that is, what is smartness? Smartness is 30% knowledgeability (what you know) and 70% intelligence (making the best use of what you know). The “Age Spectrum Study” tracked and measured 50 million (50,000,000) people for 50 years. Here is the main conclusion:
80% of older people are smarter than younger people. Note that this applies to all ages; for example, a thirty-year-old is smarter than a twenty-year-old but a fifty-year-old is smarter than a thirty-year-old.