People's scores on a test of extraversion are likely to be most strongly correlated with the number of social conversations they initiate during the course of a single group of answer choices

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Explanation: Extraversion in one of the OCEAN personality traits.  It measures how sociable an individual is.  Other traits in OCEAN are:

An extraversion test assesses qualities which point to how much a person seeks or enjoys the company of others by measuring:

A person’s score is more likely to have a strong correlation with the number of social conversations they start in a month, with highly extraverted people scoring high.  

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