Final answer:
The Flynn effect is the observation that each generation scores higher on IQ tests than the previous generation, and is linked to improvements in nutrition and education over time. The correct answer to your question is that it refers to today's population having higher IQ scores than the population of the 1930s.
Step-by-step explanation:
The Flynn effect refers to the phenomenon that each generation has a significantly higher IQ than the previous generation. This discovery was named after James Flynn, who realized that the intelligence quotient (IQ) scores have been on the rise over time. However, it's important to note that increased IQ scores do not necessarily indicate that the younger generations are more intelligent in practical terms, as Flynn himself argued. This rise in IQ scores could be influenced by several factors, including better nutrition, education, and socioeconomic improvements.
According to the choices provided in your question, the correct answer is 3) The IQ scores of today’s better fed and educated population exceed those of the 1930s population. This directly references the trend that is the essence of the Flynn effect, which is the general increase in IQ scores over successive generations.