No, they're stupid.
Orwell is careful to note that any prole who was likely to have enough brains to figure it out would be liquidated.
Happiness born of ignorance.
They are used as cattle/beasts of burden, they have no rights, commodities are always in short supply (look what happens when a few saucepans arrive) and they suffer rocket attacks.
Orwell doesn't spell out the deprivation of prole life, because it's not essential, but he makes it clear that while proles have some freedoms, their lives are generally far harsher than even an Outer Party member.