If you research some of the modern hunter-gatherer tribes, the children are held for the first year of their lives. The mother, or surrogate, essentially swaddles the child into the chest and never puts the child down. These tribes typically do co-sleeping where the child is in the bed with the mother. Very un-Ferber method.
That being said, I am not sure that it really matters. Children are very adaptable. In modern times we have methods (you know, pajamas) to ensure that the child is warm and comfortable throughout the night. We have methods (bouncers, seats, play pens) to ensure that if we put the child down he won't be trampled or eaten by wild animals.
Do what's right for your family, love your child unconditionally, and they will turn out fine... Even they cry themselves to sleep for a few nights.
No, it's about the furtherest thing from paleo-parenting imaginable. Google "attachment parenting" if you are unfamiliar with the concept. The work of Dr Sears and James McKenna will help you put babies sleep patterns into an evolutionary context. Read The Continuum Concept by Jean Liedloff.
The point of Ferber is that babies learn to sleep away from their parents. I have not consulted with the anthropologists, but I suspect it's pretty unusual historically to not sleep with your baby. Verdict: intuitively non-paleo, but I'll defer to an expert with actual data.
I have to say, though, that we shared a bed with our son and nobody was sleeping well. We didn't know how tired he was until we Ferberized him at three months. A few minutes of crying per night for a few nights and suddenly he was sleeping through the night and he was super-happy with much less cranky time. Ferberizing was just what he needed, and I don't see all these years later that is inner core has been damaged!
After that we shared a bed with our daughter. The family bed worked better this time, but at four months we felt she and we would be better off with her in a crib. That first night in the crib she sucked her thumb and fell asleep in about three minutes without a squawk, and that was that. Better sleep for everybody, and better sleep makes a happier baby.
I love the concept of attachment parenting and the child in the adult bed. Maybe the doctors are right and that's dangerous -- I'm not trying to judge whether that's true -- but just in terms of bonding it's fantastic. We would have kept it up indefinitely, but it turned out that for us and our kids it was distinctly better to have them sleep on their own, and Ferberizing was in one case quick and effective, and in another case completely unnecessary.
Ferberization may be non-paleo, but it's not the devil. At least that was our experience.
I have more to say on this than can be easily compressed into a concise answer, but I'll try.
In my gut, I could not stand to sleep more than a foot from my son, and to hear him cry on top being away from arm's reach would create unbearable anxiety beyond what I could stand. But I am also lucky enough to have been able to nap with him during the day and catch up a bit on missed sleep in the night, which likely would be what our ancestors faced.
Sleeping alone in a room, for anyone of any age I think is an evolutionarily novel concept due to lack of central heating, and living in groups larger than the single family units historically. I suspect that it is likely that kids moved from sleeping next to their moms to sleeping like puppies in little groups of siblings and cousins as they weaned, and the "skill" of sleeping alone never even came into the equation, but our lifestyles are for the most part very different today, and doing what needs to be done to survive as a whole family needs to come first.
For us sleep training didn't even work well when he was a toddler. We tried moving him to a toddler bed in our room when he was about 2 years old, and that made him extra clingy during the day, which was even more annoying than getting kicked a bit and having to fight for blankets in the night (but then again he didn't self night wean until around 3 years old, so there was a lot of getting out of his bed, coming up to me for milk, and then having to move him back, so we had to do "bedtime" multiple times per night). I like that he is so confident and adventurous during the day, and I get in a good amount of bonding time while asleep. Co-sleeping has worked well for us, but I can imagine so many situations where it would be unbearable.
But since this isn't about re-enactment, I don't think there is any "right" way to sleep for babies, humans are adaptable above all else, but that doesn't mean the choices we make for our kids won't change who they are later in life. So I think it is important for someone to do a lot of research and search their heart before taking on any sort of sleep training. Often both mom and dad need to leave early in the day to go to work, and having a baby who can self-sooth in that situation actually helps the survivability of that family unit (less falling asleep driving, more productive at work, etc.) Ideally we could change society to be more accommodating rather molding our youngest members to fit into less than ideal situations, but at least in the states that is kind of a pipe dream, so we ask our babies to adapt, which some do remarkably well.
There are studies that show co-sleeping results in more sleep for mother and baby because there is no need to get out of bed to attend to nighttime needs of the child, but then again I think it can boil down to personalities and the needs of an individual family. For a mother who cannot function without a solid night's sleep, and who is perhaps the primary bread winner who needs to return to work 6-12 weeks after the birth of the baby, I would certainly give sleep training a shot. And if that didn't work, pump and bottle feeding done by the dad, other relative, or postpartum doula. It is never a black and white issue, there are many options, and a good swaddling technique and/or sleeping in a swing can be a decent compromise for some families (a la Happiest Baby on the Block). Getting everyone as much sleep as possible should be the goal, whether that sleep is alone in a crib in a separate room (Ferber method) should matter much less.
I do disagree 100% with the idea that small babies are capable of manipulating us as many sleep training books propose, that is pure BS, what a baby wants is what a baby needs, and they only have one language for letting us know when something is wrong. Crying is not manipulation, crying is communication. If we can become master baby diplomats and communicate well enough back to a baby to make them feel safe sleeping alone, I have no problem with that. If the baby can feel confident sleeping alone and enjoy the space after a few nights to a week of whimpering, and plenty of reassurance from mom and dad, that is wonderful, but not something that I think can be universally expected.
I've read a lot about Ferber, and something that struck me as notable was in an interview years after he had written his book was that he didn't allow enough leeway for the personalities of different children, and had retracted the idea that his sleep method could be universally successful after reading letters from stressed out parents who had pushed sleep training well beyond when it was obvious that it wasn't working and getting into the area where it was likely causing psychological harm.
Long story short, is it paleo...no. Does that matter in a modern world and mean we shouldn't do it...no.
Both of my children co-slept with me as babies. Part of the reason for this is to be able to nurse when they need to through the night. It worked very well for all of us... Young babies need to feed frequently... so I question the expectation that a baby esp. under 6 months should 'sleep through the night', as if that is the normal standard, and if it's not happening your baby needs to be 'trained'.
Really, doesn't the SAD lifestyle begin with sub-par nutrition from a convenient bottle in a crib apart from the parents?
Tale of two children:
DD #1: we tried attachment parenting. It sounded so great. We quickly realized we had two incredibly sleep deprived grumpy parents who were miserable, and one whiny, unhappy baby who needed SLEEP! It took us three years and several attempts at Ferberization to get her to sleep through the night in her own bed. Every time she got sick and ended up in our bed, we'd start all over again after. Bed and nap times were dreaded by all.
DD#2: I tried a different technique beginning the very day this child was born. The idea is that you feed the child immediately upon waking. Then try to keep the child awake just long enough to lay her down when she's still awake but very close to sleep. I added a huge smile and encouraging words like "you are so smart because you can help yourself go to sleep. You are wonderful." And then you step away. The idea is to help your baby learn to soothe herself to sleep, her first skill!
OMG, what a difference! This child NEVER had to cry it out, not once! We'd lay her in her crib awake, tell her we loved her, turn out the light, and leave the room. When we laid her down, she'd smile, so happy to be in her bed. She slept through the night at eight weeks and NEVER woke us in the middle of the night. Happy, well-rested parents and baby, and she seemed healthier, too, rarely getting colds and other bugs her sister had constantly. . We could be much more attached and present with her during the day because we weren't exhausted all the time. Her infancy and toddlerhood were pure joy.
Clearly they have different temperaments, but if we used these techniques on our older child I'm certain we all would have been happier and healthier through her infancy and toddlerhood. Babies and parents need sleep, and co-sleeping just does not work for all.
Ferberization was torture for us all. I think I cried as much as she did. I'm so glad we didn't have to do it for my youngest.
The anthropological argument does not sway me. We all know that sleep is equally as important as good nutrition to our health and well-being. We got so much out of having everyone well-rested and happy. And I felt closer to DD#2 as a baby and toddler because I wasn't a crazy woman from sleep deprivation.
Being a mid-20's single male with no offspring (moreover, an only child) - I have about as little experience with children and maternal instinct as humanly possible, but: I would contend that modern coddling and overprotection that are accepted as "conscious parenting" these days creates emotional scars of its own. I don't know that Ferber was correct per se, but I think that a lot of parents could take a lesson in the fact that your child won't die if you don't present a perpetually idyllic and polished reality to them; this includes not treating every time they cry as an emergency.
I present the above from having been raised by extremely overprotective parents that would typically positively reinforce crying, whining, etc. I've struggled a lot with anxiety and sort of a perpetual subordination as such; extremely validation-seeking and never able to feel intrinsically valuable or 'enough' without someone to be enough for.
The opposite of course would be a child raised feeling a sense of coldness and distance, and as such develops intimacy issues, emotional distance, a tendency towards escapism.
I suppose the dance of parenting revolves around making the child feel loved, safe, and secure - while still giving them room to grow, explore, and learn on their own, while knowing they have someone there for them when they need it. Neurosis seem to develop when methodologies intended to do one of these things is implemented into the wrong area - such as the overprotective parent not letting their child explore the world and learn for themselves, in the name of cultivating security.
I wrote the above and realized I didn't really incorporate the paleo thing at all (this is a pretty apt psychoanalytic question, so that was my instinctual direction in replying to it). I'll leave it, as I believe it to be correct, but as a quick addendum to hopefully address your question more directly:
I don't know that we can assume that the paleo thing applies here; nurture and the expression of such is largely a social thing, and the environment in the paleo era was such that survival was still a concern, basic needs were still a question. Given this, I think that meeting needs and raising a child that lived would have been considered a success.
We should keep in mind that 1) the awareness of psychoanalytic theory, 2) the comfort required to spend all of one's time coddling a child, and 3) the context in one's life for the expression of neurosis, are all conveniences we have come to possess in a fairly modern era; with the fact that we no longer have basic needs to worry about on a day to day basis.
I do think there is something to be said for the tribal/communal raising of children, as would have likely been more common in hunter-gatherer days.