 A little island was set up in the middle of a miniature atoll, and the space between with them was filled with water.The gap was too wide for the spiders to jump all the way, and the spiders' options were to leap and then swim or to swim only.The testers encouraged some specimens by using a small scoop to make waves toward the atoll when the spiders chose the option the testers preferred (leap and then swim for some spiders, and swim only for others), and discouraged some specimens by making waves back toward the island when the spiders chose the option the testers did not want – in other words, the testers "rewarded" one group for "successful" behaviour and "penalised" the other group for "unwanted" behaviour.