"Mother is Supreme"

Okonkwo does not understand the Ibo proverb "the Mother is Supreme." He refuses to acknowledge the "female" virtues in himself and others because he thinks showing any emotions is a sign of weakness. Showing a sign of weakness could be perceived as laziness, and then Okonkwo would be thought to be like Unoka, his father. Because Okonkwo does not want to be anything like his father, he does not acknowledge emotions and such.
There are many examples of Okonkwo being unemotional and cold. One instance is when there is a meeting going on in Mbanta about what to do about the person who killed a snake, which is revered in the African culture. People were saying that the snake-killer should be ignored, and Okonkwo could not stand this. He wanted to go kill that person. When they decided not to, Okonkwo thought to himself that nothing like this would have ever happened in his village of Umuofia.
Another example was when Ikemefuna was killed. Okonkwo killed Ikemefuna, whom he thought of as a son and Ikemefuna also thought of Okonkwo as his father. The only reason he did this was because he did not want to be perceived as weak by others. And then when Nwoye found out about Ikemefuna's death, he started crying. Since Okonkwo cannot stand emotions, he beat his son for crying about the death of his brother.
Okonkwo hates emotions so much that he loses sight of the people in his family. He does not care for his son's feelings or his wives' feelings. Not only does his one-sidedness create emotional rifts between his family and him, but also between his community and him.