In John Steinbeck's novel, Of Mice and Men, George and Lennie are very different men. Their initial conversation within the opening pages of the story clearly indicates the relationship that exists between them.
Set during The Great Depression, George and Lennie travel from one place to the next, looking for work.
When the reader "meets" the two men, they have just entered a clearing with a small body of water. Thoughtlessly, Lennie throws himself down before it and drinks heavily without thought to its safety.
'Lennie!' [George] said sharply. 'Lennie, for God' sakes don't drink so much.' Lennie continued to snort into the pool. The small man leaned over and shook him by the shoulder. 'Lennie. You gonna be sick like you was last night.'
In light of these "introductory" words, spoken by George to Lennie, we find that Lennie doesn't listen very well. In this one-sided conversation, George has to call his friend's name four separate times, and still does not get Lennie's attention. George is the concerned, parental-type of the two, assuming responsibility for Lennie as he seems unable to do himself.
Although George is smaller in physical stature, of the two, he is the "bigger man:" the leader, the protector and the "caregiver" for Lennie.