Как ящик SNS определяет выбросы

It appears, by testing, that seaborn uses whis=1.5 as the default.
whis is defined as the Proportion of the IQR past the low and high quartiles 
to extend the plot whiskers.
For a normal distribution, the interquartile range contains 
50% of the population and 1.5 * IQR contains about 99%.
Real Raccoon