Hypothesis:<p>People think even numbers aren&#x27;t as &quot;random&quot; and odd numbers are more &quot;random&quot;. That leaves us with 1,3,5,7,9. 1 and 5 both divide 10 and don&#x27;t seem so &quot;random&quot; to us, I guess. That leaves us with 3, 7, and 9. 33, 77, 99, i.e. numbers with repeated digits don&#x27;t seem so &quot;random&quot;. That leaves us with 37, 39, 79. And 9 maybe (not sure if all people subconsciously think this way) isn&#x27;t that &quot;random&quot; because it&#x27;s one less than 10 and divisible by 3.<p>Infact, the jargon file says that 37 is the most common random number people will choose[0].<p>[0] <a href="http:&#x2F;&#x2F;catb.org&#x2F;jargon&#x2F;html&#x2F;R&#x2F;random-numbers.html" rel="nofollow">http:&#x2F;&#x2F;catb.org&#x2F;jargon&#x2F;html&#x2F;R&#x2F;random-numbers.html</a>