Jennifer Garner's son is a ''total mama's boy''.

The actress - who already has daughters Violet, six and three-year-old Seraphina with husband Ben Affleck - gave birth to Samuel six months ago and according to friends, finds raising a son completely different.

The pal told Us Weekly: ''Samuel's at an age where he is starting to do more. He has been so much fun for her and such a different experience from the girls.

''He is super chill and go-with-the-flow, but a total mama's boy.''

Although she has taken time out of her career to focus on raising her kids, Jennifer has previously admitted worrying about what is best for her children keeps her awake at night.

In her blog for the iVillage blog series CelebVillage, she revealed she thinks it is difficult to strike a balance between encouraging children to pursue a hobby and be good at it or allowing them to quit if they decide they don't enjoy the pastime anymore.

She wrote: ''Did you watch the Olympics and vow to double up on your Judo Prodigy's lessons?

''Now, when you see that your child hates the extra lessons and would rather build Star Wars Lego cities, what do you do? Do you push through until they like it again or... do you let them quit and risk the future admonitions for letting them give it up - OR - do you find a Lego specialist?

''This is the kind of mothering conundrum that keeps me up at night. How do I know if I'm getting it right?''