You have an IQ of 140+ if you can find the missing number in this picture in 9 seconds. Can you? Test your intelligence now!

Another study has shown that intelligence is not fixed throughout one's lifetime: Teens' IQs changed by as much as 20 points over four years, raising questions about some modern IQ test uses.

An intelligence quotient (IQ) test is a way to assess cognitive abilities, and gives you a score from a set of standardised test. It's designed to assess human intelligence in areas such as ...

Article continues below IQ test challenges you to work out next number in 'tricky' maths sequence (Image: quiz_riddles/Twitter) ...

Just a few years after Terman brought the IQ test to the United States, it left the classroom--and entered the military. During World War I, the number of army recruits exploded from around ...