Factfulness is … recognizing the assumption that a line will just continue straight, and remembering that such lines are rare in reality. To control the straight line instinct, remember that curves come in different shapes. •   Don’t assume straight lines. Many trends do not follow straight lines but are S-bends, slides, humps, or doubling lines. No child ever kept up the rate of growth it achieved in its first six months, and no parents would expect it to.




