Justin Bieber, Beyonce, Natalie Portman, Denzel Washington: Six Smart Celebs

Call it petty jealousy but a lot of superstars labour under the label of being a little, er, unintelligent.

But teen heartthrob Justin Bieber has joined the growing ranks of celebs who have brains as well as beauty, talent, fame and cash after graduating from high school.

The 18-year-old Baby singer may already have the world at his feet and millions in the bank but he still insisted on making his mother proud the old-fashioned way - by getting his education.

He said: "I just finished high school," he said. "I passed my test - I'm free! It was hard doing school and work every day."

The singer, who is dating pop star Selena Gomez, explained that he had completed his high school education at the request of his mum, Pattie Mallette.

"School was something my mum really wanted me to do so I had to do it for her," he said.

"This kind of lifestyle has given me a different perspective on life. I've been able to travel the world. At school, usually you have to do a lot of writing and reading. I'm really not into that stuff. I like to be out there," he added.

Other stars have made getting an education under their belts a high priority.

IBTimes UK looks at a few stars who refuse to conform to the "stupid" stereotypes assigned to them...