Stanley Yelnats, the main character in Holes by Louis Sachar, possesses many character traits. Here are five of them:

Stanley has a strong belief that his family is chronically unlucky, and believes that the source of this misfortune is a curse that was placed on his "no-good-dirty-rotten-pig-stealing-great-great-grandfather," Elya Yelnats. Because of his absolute belief in the family curse, Stanley is never particularly surprised when bad things happen to him.

Stanley lacks self-confidence. He is described as an overweight boy who gets picked on a lot at school and does not have any friends before he arrives at Camp Green Lake. This is a trait that changes over time, as his self-confidence improves over the course of the book.

Despite Stanley's belief in the curse, he remains hopeful and tries to maintain optimism. This is a trait he shares with his family, who don't have much money but look for the bright side of life. This trait helps him survive the abusive situation he finds himself in at Camp Green Lake.

Stanley is intelligent. This is apparent throughout the book, but it is especially noticeable when he begins finding intriguing items in the holes he digs. He is able to piece together parts of the mystery of the book and realizes that they are not digging holes to "build character," as they've been told. They are digging holes to find something the warden wants, and badly. Using the knowledge he has, he is the one who realizes that they are looking for the lost treasure of Kissin' Kate Barlow.

He is kind. His kindness shows as he helps Zero learn to read and as the two become closer friends in spite of the way that affects Stanley's social status with the other boys. He stays true to his friend and even sacrifices his own safety to try to save Zero's life by following him when he runs away.

Stanley is fourteen years old and one of his major character traits is his feeling of inferiority. He thinks the curse that has been on his family also affects him and so feels like he should accept the bullying of his classmates and his difficult life.

Another character trait he had was that he was unwilling to accept the blame for his own mistakes. He simply transfers the blame to his great-great-grandfather and can be pretty impertinent about it.

Stanley is generally a good person, however, and certainly is not eager to cause anyone harm. The fact that he gets blamed for stealing the shoes is ironic because he really hadn't done anything wrong and didn't deserve the harsh punishment.

Stanley is also caring. Immediately upon arriving at the camp, he begins to make friends because he goes out of his way to be nice to other people and stand up for the boys. 

Stanley demonstrates courage by being willing to take the rap for crimes he didn't commit at camp. He does so in a couple different occasions and this raises his esteem amongst the boys tremendously.