According to Abraham Maslow's hierarchy of needs, self-actualization - realizing one's full and unique potential - is the pinnacle of human motives. The traditional view of self-actualization is that it's above the lower biological and social needs. But if self-actualizing is a universal drive, the researchers wanted to know whether it promotes biological fitness (also called Darwinian fitness, and refers to the ability to pass on one's genes to future generations) and/or social motivations.
This is what Brazilian neuroscientist, Suzana Herculano-Houzel, aimed to find out. The African elephant brain is three times larger than ours, but did it have more neurons? Over a period of six months, she and her students sliced an elephant brain by hand, separated out the different brain structures, and processed them into 5 gram pieces. The pieces of brain were stained and the neurons counted by hand.