The method of choosing the first box at the right end and then the one
next to it developed in the case of all except two of the ten settings.
The time of appearance is worth noting. In setting 1, it failed to
appear; in setting 2, it developed early,--after about one hundred
trials; in setting 3, after about one hundred and fifty trials; in
setting 4, after about one hundred and fifty trials; in setting 5, after
about one hundred and seventy trials; in setting 6, after about one
hundred trials; in setting 7, after about fifty trials; in setting 8, it
never developed; in setting 9, after about fifty trials; and in setting
10, it developed very late,--after about four hundred and seventy
trials.

This method of reaction, although inadequate, proved remarkably
persistent, and it is doubtful whether it had been wholly overcome at
the conclusion of the experiment. In the case of the series of trials
given on June 8, numbered 191 to 200, the method used was either that of
the first at the right and then the next, or direct choice of the right
box.

Throughout the trials with this problem, the end boxes, numbers 1 and 9,
were avoided. This is at least partially explained by the fact that they
never existed, and obviously never could appear, in problem 2, as right
boxes. In trials 601 to 610, given on July 7, there occurred partial
return to the formerly established method of choosing the first door at
the right. This relapse was characteristic of what happened during the
many days which intervened between the definite appearance of this habit
and the final solution of the problem.

Especially in connection with such relapses, Skirrl showed extreme
fatigue or ennui and often would refuse to work and simply sit before