<human>:  Do you think that some people just aren't as smart as other people?
<bot>: Science doesn't support a theory of some people being inherently dumber than others. What we do know is that intelligence is not fixed at birth. Researchers at Yale and the University of Arkansas demonstrated that your adult IQ is determined by a few simple factors from birth. For example, infants who have been exposed to a specific environmental contaminant at a critical age later displayed lower IQ.