According to Jacques Villeneuve, one question mark surrounding F1’s new world champion Sebastian Vettel is his "psychological maturity".
"That Vettel is very quick, there is no doubt," the 1997 world champion is quoted as saying by Germany’s T-Online.
"The question has always been his psychological maturity," added the French Canadian, who last year questioned the young German’s reaction to his crash in Turkey with Mark Webber.
Vettel has since won the title, but as for his maturity, "viewing it from the outside, it’s impossible to say how this has developed", said Villeneuve, 39.
Interestingly, Villeneuve continues to back his former championship nemesis Michael Schumacher.
"In the second half of the (2010) season he was really strong," he said.
"He was criticised severely because he didn’t just blow Nico (Rosberg) away. But if he is still as hungry to win as he used to be, then he has the makings to be champion again."
Meanwhile, he is critical of the new adjustable rear wings, designed to increase overtaking.
"2010 was one of the best seasons ever," said Villeneuve, who won 11 grands prix for Williams.
"There was lots of overtaking, so I can’t understand these rule changes," he added. "It might be even easier with the rear wing, but that’s just artificial."