Role in the series
Goku is known for his cheerful, energetic personality and his love for competition and eating. He will eat anything. He has remarkable intuition to see the good in others in spite of their actions, though his capacity for forgiving has occasionally been criticized as excessive; Goku, mostly fights to win and often spares his enemies even if they in turn attack him. His staggering power is simultaneously reined in and enhanced by his fierce loyalty and morality. Goku can be very blunt and not afraid to express his opinion in a discussion. While generally kind and not intentionally rude, Goku tends to not show proper respect to people of high authority. Despite his kind-hearted nature, Goku can feel incredible anger in extreme situations such as the death of a friend/relative or innocents murdered, showing he can be vengeful. He has a simple, practical view of the world that often comes off as naïve, which often makes many incorrectly assume him to be somewhat stupid. While often taking things to face-value, he comprehends the situation quickly and learns the basics of anything presented to him rather quickly. His most remarkable ability is his will and tenacity to succeed, always determined to push himself beyond his limits and never give up even in such overwhelming adversity.
Goku is pure of heart, possessing no negative feelings or thoughts. He is also shown to be very innocent since childhood, because of growing up in Mount Paozu and not having met anyone other than his grandpa until he meets Bulma. During his childhood, he had difficulty telling the difference between a male and a female without physically touching them, which often gets him into trouble, until he eventually outgrew this once old enough to understand the difference. Despite his compassion for others, Goku might not have a sense of family, but rather views family simply as companions.. To which, he did not seem to understand romantic love and mainly married Chi Chi because he promised. Even more, Goku has rarely shown any romance with Chi Chi in their marriage (although in the anime Goku has told Chi Chi he loves her and kissed occasionally). Along with this, Goku tends to priorities his training over all else, often choosing to train rather than meet with his friends (although many of the Z fighters tend to due this). He will often leave his family for long periods, and although always for noble reasons, Goku doesn't how this effects his family. Despite this, Goku has shown to have genuine loyalty and compassion for his family and friends, shown from his visions of them during his battle against Frieza.
Goku is shown to be scared of overbearing women like Bulma and Chi Chi. During the Frieza Saga, when Goku refused to come back to Earth, Master Roshi teasingly said that Goku was too afraid to face his wife. In Battle of Gods, Goku panicked when he realized he forgot to go to Bulma's birthday party. Over the years, Goku has shown little modesty, not at all concerned about being nude in public. Goku's love for food can be comical at times. In the Tournament Saga, when put to sleep by "Jackie Chun", Bulma was able to save his match by screaming to him that dinner was ready, to which Goku immediately woke up to break the count.
Goku seems to think very little of his Saiyan family, never knowing the good traits of parents. Even more, when he first learned of his Saiyan heritage, he rejected it out of horror and disgust at being from a race of vicious killers, though he ultimately embraced his heritage after hearing Vegeta's last words during the battle withFrieza on Namek, fighting him to avenge the loss of his race as well as all of the other innocents whom Frieza had killed. While Goku is unquestionably kindhearted, forgiving, and loyal to the side of good, his Saiyan bloodline and its traits for combat have played a moderate role in his judgment, such as staying on the self-destructing Namek to finish his fight with Frieza. He can also be reckless in his gambles; when realizing that Gohan's dormant capacities could defeat Cell, he chose not continue training and instead trust his son to face the monster, forgetting that Gohan was even gentler than him to the point of being a pacifist.
While not arrogant in his abilities, Goku has a tendency to be to relaxed and confident he can compete against anyone, a trait which can often lead to him letting his guard down as seen in Dragon Ball Z: Resurrection ‘F’, where - believing he has defeated Frieza - failed to notice Sorbet aiming his laser at him and resulting in Goku being critically injured.