Final answer:
The incorrect question proposed about intelligence by psychologists is the idea that an individual's intelligence is determined solely by the intelligence levels of his siblings. This concept does not align with the broader research and discussions that focus on measurements, genetics, environmental influences, and IQ test validity.
Step-by-step explanation:
The question asks which of the key inquiries posed by psychologists about intelligence does not belong. The correct option that does not represent a common question psychologists explore is 'An individual's intelligence is determined solely by the intelligence levels of his siblings.' Psychologists do ask questions about how intelligence is measured, the relationship between genetics and intelligence, how intelligence changes over the lifespan, and why intelligence varies among individuals and groups.
Intelligence has been a subject of scrutiny and debate for many years. Differences in intelligence measurements, genetic factors, environmental influences, and the validity of IQ tests are vital themes in understanding intelligence. It's crucial to acknowledge that there is a consensus among researchers that individual intelligence cannot be determined solely by the intelligence of siblings, and this belief is not reflective of the broader research and conversations around the concept of intelligence.