Tanner's main motivation is the Insane trait. He is a wild and irresponsible Sim whom obsesses over Vegas and gambling, which he hopes to get into when he becomes a Young Adult. Lifesimmer believes that Tanner will someday win big either gambling or playing the lottery.
Season 2
Tanner grew up into a Toddler in Part 28. He was sent to the Fort Starch Military School off-camera and escaped in Part 44, returning two days before becoming a Teenager. Tanner aged up in Part 45 and carried on with military school. Subsequently, he could not attend Kendra and Andrea's wedding.
Season 3
Tanner is now living in Maple Cove. Having left military school, he is failing public school horribly. Tanner has dyed his hair bright blue and now has a Vegas-themed bedroom. He does not have a good relationship with anybody in the household: he is constantly reprimanded by his parents and older siblings alike, and is the only one of the boys not to be invited out fishing with Zane.
Gallery
Tanner as a baby
Tanner as a Toddler
Trivia
Tanner has a very unusual glitch: when he aged up into a Child he didn't get a third trait. This was fixed by Lifesimmer when she gave him the Insane trait, which runs in his mother's side of the family.
Tanner is the only Santiago child not to have attended Kendra's wedding.