Villa have accumulated 65 bookings and two red cards during the current campaign and lie at the foot of the Fair Play table ahead of Saturday's encounter at Stoke.
Lambert accepts some of the cautions have been justified but also feels the age of his players has been a factor in the number of cards Villa have received during 2012-13.
He said: "I think some of our bookings are because we are young and it's an easy target.
"It can work against you if you are young. We have deserved some bookings but some we haven't, that's for sure.
"Are officials more inclined to book younger players? I hope that won't be the case because you are an equal on there (the pitch).
"But I think some of our bookings have been unjustified.
"Some of the challenges have deserved yellows but some are there I never thought should have been bookings.
"It is up to the referee who is officiating whether they think it's right or not."
Lambert insists Villa, who dropped into the bottom three of the Barclays Premier League for the fifth time this season last weekend, are not a dirty team
But he expects his players to be competitive at the Britannia Stadium against the physical challenge provided by Stoke.
Lambert said: "You have to be fair. We never send anyone out to hurt anybody.
"We don't have the players for that. We try to compete the best we can.
"You can never curtail anyone the way we play but we haven't got a nasty team.
"You know it is going to be a hard physical game against Stoke, that's for sure, and we have to match them."
Lambert confirmed defender Ciaran Clark is still troubled by the shoulder injury which forced him out of last weekend's home defeat by Liverpool.