Answer:
The correct answer is - the average lifespan.
Step-by-step explanation:
As it is mentioned in the provided question that the experiment is design to measure how environment and the genetics shapes who we are which means effect of genetics and environment that is responsible for our present selves.
Generally such experiment include various variable that can affect the experiment on different level. The least useful information or measurement is the average life span of the population as it can vary and depends on several other factors than the genetics and environment directly.
Thus, the correct answer is - the average lifespan.