Concentration speed and accuracy were measured using an online
numbers-matching test (www.psychtests.com/tests/iq/concentration.html)
that consisted of 26 lines of 25 numbers each. In 6 minutes, participants
were required to find pairs of numbers in each line that added up to 10.
Scores were calculated as the percentage of correctly identified pairs out of
a possible 120. Perseverance was measured with a puzzle that contained
five octagons—each of which included a stencil of a specific object (such
as an animal or a flower). The octagons were to be placed on top of
each other in a specific way to make the silhouette of a rabbit. However,
three of the shapes were slightly altered so that the task was impossible.
Perseverance scores were calculated as the number of minutes that a
participant spent on the puzzle task before giving up.