Psychologically, what is the best age at which to separate a puppy from its mother for adoption?

As others have said, at least 8 weeks is best. I would say a MINIMUM of 6 weeks. depending on the circumstances and if the puppy owner is experienced with young puppies.

I have a dog that was abandoned at 6 weeks old. She went to an excellent foster home for a couple weeks, then a shelter where I adopted her. She has been the BEST dog ever.

12 weeks of age would be the best age IMO for the average pet owner seeking to get a new puppy.

At that age the puppy has a stronger immune system. At 12 weeks a puppy has already had time enough to learn "bite inhibitation" from its littermates and siblings, making it less likely to be a chronic biter and more easier to train NOT to bite. **Bite Inhabitation** is IMPORTANT!

Also at this age, the puppy has had plenty of time to socialize with its littermates and dam so it will be less prone to "separation anxiety", and neurotic aggressive behaviors towards other new dogs/animals.

Good breeders give their puppies tons socialization and human interaction so the bond between dog, littermates and puppy is easily gotten over once the puppy goes to it's new home.

Mom is ussually done with the pups by 8 weeks, they mostly attain vital social skills by spending those last few weeks with their littermates.

A pup who is still quite immature at 8 weeks (very tiny, not eating hard kibble, or still nursing regularly) may need a few more weeks. Small breeds often stay with mom until 10-12 weeks, and some breeders, especially those with very tiny puppies, keep them as late as 16 weeks. The other issue with small puppies is the risk of hypoglycemia (low blood sugar). A puppy who is stressed about leaving mom and littermates may not eat enough as it adjusts, and the stress of the change can trigger the blood sugar to drop. Giving a tiny puppy a few more weeks to mature and gain some more body weight helps reduce this risk.

Leaving a pup with its mother over 8 weeks of age can have the effect on the pup of bonding too strong with its litter mates and the trauma of leaving them is a lot more traumatic with the result the pup can take a lot longer to settle into a new environment on its own without the support of its siblings.

Of course the severity of it depends on the pups basic temperament as bold dominant pups cope with life easier than shy or nervous ones.

Very tiny miniature breeds of dog may benefit from staying with mum a week longer than 8 weeks but for normal size breeds 8 weeks is the recommended age.

Many experienced working dog owners prefer to get their pups at 6-7 weeks old as at this age they do tend to settle into a new environment very fast, bond with an owner easier, and they do very often learn dog manners from the owners other adult dogs.

A few decades ago, it was the norm to get a pup at 6 weeks old, and they did NOT suffer behaviour problems at all by being removed from Mum and the siblings.

I can vouch for that, having had quite a few pups at 6 weeks old over 54 years of dog ownership.

The best dog I ever owned was just 6 weeks old when i bought him and was an ambassador for his breed, excelling in working dog trials, and had a great temperament.

But so called experts on animal behavior have now deemed it wrong to take a pup before 8 weeks old. And probably for the best considering all the inexperienced and ignorant dog owners that seem to be out there in this world. You only have to read most of the questions on the Dog section of Yahoo answers to come to that conclusion.

Your question is very debateable though and many will have their own views about this issue. This is mine.

Ps: Once the pup is taken away from its mother its not adviseable to take it for return visits or try and remind it of its mother by blankets that smell of her. A clean break is best for the puppy.

Eight weeks is the MINIMUM time that a pup should spend with its litter - 10 to 12 weeks would be much better. Puppies learn dog body language and social skills and important bite inhibition during this time. You do your dog no favors by removing it from its littermates before 8 weeks of age.

8 weeks for most dogs. 10 weeks for smaller toy breeds.

8 weeks, minimum. 10-12 weeks is ideal.

8weeks is best .take the dog home and that is it