A recent study has shown that neurogenesis took place in male mice in the days following the birth of their pups. But the extra boost of brain cells only occurred if the mouse father stayed in the nest. In other words, if he was removed on the day of their birth, nothing happened. One new set of brain cells formed in the olfactory bulb, and were specifically tuned to the smells of his pups. Another set of neurons grew in the hippocampus, a crucial memory center in the brain, which helped to consolidate the smell of his pups into a long-term memory.
In mammals, neurons located in the nose detect scents using special odor receptors, and shuttle the information to the olfactory bulb, which is the integration center for smell. Yet smelling his pups alone was not enough to cause new neurons to form. When the researchers separated the father from his pups by placing a mesh screen between them in the cage, no additional brain cells appeared. The father had to be physically present in the nest in the early postnatal days to get another dose of neurons. The physical contact he had with his pups in the nest coupled with the smells of his young are what made the neurons grow.
The brain cells that formed when a father interacted with his offspring were also regulated by a hormone called prolactin. This means that the same hormone responsible for milk production in the breasts of new mothers also seems to be involved in fostering the postnatal connection between a father and his offspring. Mouse fathers that had the prolactin gene turned off did not form any offspring-specific brain cells.
Being separated for a few weeks time is usually long enough for adult mice to forget their cage mate pals. But these new neurons helped to form long-term memories and bonds, as the mouse fathers easily recognized their offspring by smell even after they had been separated for a long period of time.
While it appears the seed of the father-child bond is planted by supplemental neurons in a new dad, it seems a child, on the other hand, may be born with a brain that expects this bond to form in the first place.
To prove this, a few recent studies turned to a rodent that employs a remarkably familiar nest structure. Degu rats are biparental animals, which means parenting duties are split between the mothers and father. Degu fathers behave just like human fathers. They spend the early days of their pups’ lives helping with basic care, like warming and grooming. And as the pups get older, the degu fathers begin actively playing with their toddler offspring.
Researchers reasoned that absent fathers in the degu nests would create a true social and emotional void for the offspring, just as a missing dad would impact the dynamic of a human family. They found that if a rodent father remained in the nest with his pups – presumably due to the newfound bond with his offspring – his babies’ brains developed normally. But if the father was removed from the nest shortly after the birth of his pups, his newborns’ brains started to break down at the level of synapses, which are short chemical junctions in the brain that allow brain cells to communicate with each other.
Specifically, the degu pups raised without fathers had fewer synapses in both the orbitofrontal cortex and the somatosensory cortex. Having fewer synapses can alter the way information is processed in the young animals, and would make these brain areas perform abnormally.
The orbitofrontal cortex is a part of the prefrontal cortex that regulates decision-making, reward, and emotion. Extrapolating from the degu rat experiments, faulty synapses and processing problems in this locale may ultimately explain why we see some kids who grow up without a father in their life wrestle with (sometimes very serious) behavior problems.
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Add CommentAll these DHHR workers who tell mothers that their child will be just fine with one parent and they will even get more money from the deadbeat dad that they just created should read this article...and they wonder why our prisons are so over populated.
Reply | Report Abuse | Link to thisThe survival and advancement of our species is very important; parenting classes should be required in school from 1st grade through graduate school. ...but that will never happen.
Great article. It was nice refreshing my memory on how important both parents are in growing a child.
A nice story but the shame is that the concept of "dad" is still the source of most sit-coms, movies and whatnot depicting "dad" as a lumbering neanderthal, glued to the TV watching the "game." Never found that very entertaining and wish we could all move past this depiction.
Reply | Report Abuse | Link to this"Specifically, the degu pups raised without fathers had fewer synapses in both the orbitofrontal cortex and the somatosensory cortex. Having fewer synapses can alter the way information is processed in the young animals, and would make these brain areas perform abnormally. "
Reply | Report Abuse | Link to this- I wouldn't jump to conclusions and say "abnormal". It is possible this is an addaptive reflex programmed by evolution. After, death of a father was probably a common thing and would require change the offsprings behavior in life drastically.
Also, I wonder if what they found is really a father-child bond; perhaps its just an adult-newborn bond. They should try the same experiment, except with a rat that isn't the father, rather, a rat whom has never seen a newborn.
They are sitcoms, what did you expect, enlightened, intelligent discussion by educated, committed fathers? Hardly entertaining to the masses.
Reply | Report Abuse | Link to thisFor a much more intersting take on parenthood, try watching Parenthood. Its funny and intelligent, with no neanderthal dads in sight.
gunslingor - Good point. As I understand, some rodent species form permanent pair bonds, others do not. For those that do not, it could be expected that the offspring would all exhibit the developmental distinctions of fatherless Degu rats - "abnormal" would be normal.
Reply | Report Abuse | Link to thisHowever, this report states:
"Extrapolating from the degu rat experiments, faulty synapses and processing problems in this locale may ultimately explain why we see some kids who grow up without a father in their life wrestle with (sometimes very serious) behavior problems."
Perhaps the central conclusion of this research might warrant some experimental confirmation, at least to determine whether "fatherless" rodent species produce offspring with detrimental behavioral characteristics. As that would produce a negative survival trait, there may be some other factors involved...
Unfortunately, this doesn't cover what happens once the newness of a baby wears off, and what happens to the father/child's development once a father removes himself from the child's life later on.
Reply | Report Abuse | Link to thisThe bond doesn't last long with many fathers. I'm interested to find out how the brain is able to completely reverse itself in this situation. And, the impact t has o the still developing child's brain...
Also, how much of this could be ego related and not neuroscience?
It's a very interesting study.
I find it interesting that the article ASSUMES that the extra presence in the nest (or for humans, around the house and in contact with the offspring) is the biological sire of the offspring. It has been convincingly argued (see the recent book "Sex at Dawn") that the nuclear family unit is a post-agricultural phenomenon and that the natural "family" configuration for humans is a band of humans among whom child care is freely shared and who do not necessarily form traditional marriage-like bonds. How does this fit with the "science of fathering" characterized in the article? And can it be shown that families with two same-sex parents cause some kind of deficit in the offspring? I doubt it.
Reply | Report Abuse | Link to thisFollowing on from jdnene's comment, I would be interested to if this is reversible, and changes are made later in life if a father removes himself. Does an adopted of stepfather also trigger similar changes?
Reply | Report Abuse | Link to thisI believe that the 'natural family' grouping being a band of people with shared childcare is really an historical artifact from a time when humans did live in large groups and needed to share child rearing because of a need to work so hard to provide for all members of the group and because of significant mortality - of infants as well as mothers and fathers. What was 'natural' hundreds or thousands of years ago does not always carry over to the present.
Reply | Report Abuse | Link to this@byjove,
Reply | Report Abuse | Link to thisI rather like you bringing up the hunter gatherer idea. I honestly do believe efforts to understand human nature should focus on what got us where we are today (IE the actual environment we spent the longest in prior to culture and technology making our functional environment somewhat more arbitrary). Having said that, sharing child care responsibilities is not the same as arbitrarily doing away with the concept of parenthood (which is alive and well in most hunter gatherer societies. I often find that the same people who suggest otherwise idealize hunter gatherer groups in other ways too like suggesting they don't utilize status at all unlike folks in modern agricultural/industrial societies. Incidentally, that isn't true either), Also I do think that both infants and parents are capable of bonding on a much more specific basis. For starters the sense of smell is key to lots of what goes on. Through smell it is very easy for most mammals (including humans) to gauge how closely related a given compatriot is to them. Other research has shown that mammals including people exude certain compounds in their sweat that are detectable by others and that these compounds present a pretty good profile of their immuno type. Mice and people both find individuals with profiles as distant from their own as possible more attractive. It's thought this gives offspring a better shot at having a widely varied and effective immune system. It's interesting to note that pregnant mice have their preferences flip to preferring the smells of close relatives. On that basis a mechanism does, indeed, exist for a preferential father child bond.
I hope you are not implying some form of politicizing on the issue is going on in the article with your comment about same sex couples and parenting. It's a well established that children of step parents (regardless of the nature of the coupling) are at greater risk of abuse and neglect than they are at the hands of biological parents. This in no way implies that all step parents are bad (I raised three step children myself and did a good job of it I might add), or even that all biological parents are good. It just is. Feel free to ask your neighborhood social worker about the statistics if you don't believe me.
Healthy skepticism is good in any field of endeavor, but occasionally I encounter skepticism that smells and awful lot like an objection based on how one thinks things 'ought' to be rather than on any well founded argument.
Brian Mossop has obviously never been pregnant! He appears to confuse the womb with an isolation or sensory deprivation tank. He describes the infant as "Having spent the prior weeks with (touch) senses deprived while 'afloat' in amniotic fluid.." Infants and mice are anything but touch deprived, especially mice, where there are multiple pups in the litter! They are in constant motion and any mother can assure you, squeezed from all directions! I would never refute that synapses of the somatosensory cortex are further developed by postnatal contact with (a) father, but it certainly doesn't stem from previous sensory deprivation!
Reply | Report Abuse | Link to thisMy second point is a question. What about adoptive parents? Do the same synapses develop in both the infant and the father (or mother) if they are not the biological parents?
quote attributed to John Money
Reply | Report Abuse | Link to this"We don't know what the sense of smell has to do with human sexual development. For all we know, the underarm smell of an infant's father may be crucial in his life! You're laughing, and I'm almost joking. But almost no theory is too wild as we've been learning." -- Karlen, A. (1971) Sexuality and Homosexuality: The Complete Account of Male and Female Sexual Behaviour and DeviationWith Case Histories. (pages 402) MacDonald: London.
quote attributed to John Money
Reply | Report Abuse | Link to this"We don't know what the sense of smell has to do with human sexual development. For all we know, the underarm smell of an infant's father may be crucial in his life! You're laughing, and I'm almost joking. But almost no theory is too wild as we've been learning." -- Karlen, A. (1971) Sexuality and Homosexuality: The Complete Account of Male and Female Sexual Behaviour and Deviation‑‑With Case Histories. (pages 402) MacDonald: London.
Interesting, but research *actually* shows that children of single mothers (or fathers) fare just as well as those of two parent families, provided that the mother is adequately supported, ie has a support network, isn't in poverty, etc. Obviously the child of a family that has experienced the trauma of a breakup, has an overworked mother, is in poverty, is forced to live in an area with high crime, and endures the stigma of being a sole parent, is not going to fare as well as the child from the socially normalised well supported nuclear family with all its resources.
Reply | Report Abuse | Link to thisThat difference has nothing to do with biology, and everything to do with sociology.
Unfortunately this article has no information whatsoever on what the changes in a father's brain might be, but a lot of *misinformation* on children of single parent families.
Unfortunately the argument about step-parents is again, a poor understanding of sociology, or pre-conceived notions of what is 'natural', misdirecting our understanding of biology.
Reply | Report Abuse | Link to thisStep-parents are more likely to abuse their children. Again, this is a function of the tension inherent in a blended family (some overcome it of course).
*Adopted* children are less likely to be abused than any others.
What is going on in is *social* not biological.
This is the big problem with evolutionary psychology. It looks at how things are, and then tries to extrapolate an evolutionary mechanism that often just does not exist.
The example that someone mentioned re the nuclear family v collective childrearing is the perfect example.
In fact, the nuclear family is not 'natural' at all. Humans evolved to share childrearing as a group (men included, btw!)
Bah lost my other comment - it's true that stepparents are more likely to abuse their children than biological parents. But what is also true is that adoptive parents are least likely to abuse thier children.
Reply | Report Abuse | Link to thisThe incidence of abuse in blended families is a function of previous trauma and tension - not biology.
It's about sociology, not biology.
Gunslingor: "Also, I wonder if what they found is really a father-child bond; perhaps its just an adult-newborn bond. They should try the same experiment, except with a rat that isn't the father, rather, a rat whom has never seen a newborn."
Reply | Report Abuse | Link to thisThat is a really excellent point - I have no doubt that a real (at brain level) bond exists between my husband and our kids, but I tend to think it arises through general (biological) bonding processes and not a bonding process specific to father-offspring, and it is of course hugely enhanced and nourished by the socialisation of fatherhood.
A *huge* proportion of men, sadly, abandon their children - children that they wanted, were there for the births of, etc, a fact this hypothesis fails to account for.
Those who think that sociology is more important than biology to family dynamics might want to become more familiar with the role of genetics (i.e., biology). In all non-human mammals studied, genetic diversity (as conveyed by olfactory/pheromonal cues) influences bonding. If an infant male smells too "different" he may be killed by the stud male. Puberty is advanced in genetically diverse females, and retarded in genetically similar females.
Reply | Report Abuse | Link to thisGonadotropin releasing hormone (GnRH) controls the concurrent maturation of the mammalian reproductive system, the neuroendocrine system, and the central nervous system. Oxytocin production provides feedback to the GnRH neuronal system; oxytocin causes nothing. Mammalian pheromones directly effect GnRH pulsatility, and thus effect secondary neuronal systems that are important to species survival. Neuronal systems that are downstream from the GnRH neuronal system, provide some interesting correlates when they are linked to different behavior. However, statements of cause and effect demand that the pathway: gene-cell-tissue-organ-organ system, be detailed before the stimulus can be linked to the response (again, that's biology). Social science tends to ignore the aforementioned levels of biological organization, which allows social scientists to link anything to anything (e.g., oxytocin and bonding). Minimally, at least two levels of biological organization should be addressed by studies that attempt to link this with that. In this case, the effect of pheromones on GnRH pulsatility and thus on oxytocin is what conditions the behavioral response associated with oxytocin release. Obviously, there is no direct link from touch to oxytocin release (or to changes in the brain), and social influences do not operate outside biological constraints.
Whoever thinks that childhood development is solely a function of either biology or sociology, is sadly mistaken: both obviously are critical influences in the development of human beans. Any of you Scientific Americans ever been to Japan? You might gain some valuable perspective.
Reply | Report Abuse | Link to thisYou've not replied *at all* to anything I said.
Reply | Report Abuse | Link to thisStudies - on humans, not animals - have shown that children of single mothers who have good support networks perform in exactly the same way as children from 2 parent familes (from *stable* 2 parent families I should specify - 2 parent families with tension in them have lower performing children).
Adoptive parents - including fathers who by extrapolating from your 'non-human mammal' study should apparently sniff a difference - are least likely to abuse.
Evolutionary psychology - bad science. It's all about naturalising the norm. We don't actually know what the norm is.
Extrapolating from what a non human species does in a lab experiment does not reveal information about the human species. We behave significantly differently from our closest genetic relatives.
What we can do is look at the thousands of human cultures in existence and gather information.
Fatherhood is not a given, it is a cultural construct.
There are *hundreds* of cultures in which biological fatherhood is not recognised at all.
In many cultures, the uncle takes on a father role (as we define father, in western society). In many, many cultures, the father has no role. The mother is primary carer, and extended family supplement her caring as the child gets older (ie as physical dependency lessens).
Unfortunately there's been no attempt to directly address the *actual state of affairs* that really exist in the human species, but only vague what-ifs and far-fetched extrapolation from non-human (un-named) species.
Not everybody lives the way that white middle class Americans do. Yet all too often, 'science' takes this kind of society and sets it as default, then works backwards.
There may be any number of mechanisms at work in a study that finds that father (of whatever species you refer to, as you didnt identify, could be a mollusc for all I can tell) react badly to offspring who aren't genetically related - it could be the trauma of having their mate upset, their cage changed, who knows.
The fact is, human beings don't have stud males. We evolved to raise children in a cooperative arrangement, in which many adults collectively raise children. Having one man go about sniffing and killing any child who isn't his (assuming he even has such a concept) would hardly promote survival of the species.
Of course - it's both! For example, a child may have biological or sociological factors behind 'acting up' - undiagnosed ADD, or inattentive caregivers, or any number of factors. What we can establish is that it won't be simply due to an absent father - not without other factors.
Reply | Report Abuse | Link to thisAnd my brother lives in Japan :)
I'm not American btw.
Maire - I'm not really Scientific, either.
Reply | Report Abuse | Link to thisPerhaps then you already have some appreciation for how varying social conditions can affect behavior. Certainly parental relations can affect resource availability, social status and many other dependent factors contributing to child development.
This study seemed to do little to establish any relationship between any biological effects identified and behavioral results. That biological effects of parental relations can be identified is significant. However, 'extrapolating' effects from experimental results to construct conclusions is hardly scientific.
It's sometimes seems like people should try and keep in mind that well balanced, well adjusted people oftentimes come from less than ideal situations, and people with problems and imbalances can and oftentimes do succeed in overcoming these sorts of obstacles without radical "brainwashing" techniques or experimental drug therapy. Self realization can be the most powerful thing in the world.
Reply | Report Abuse | Link to thisBeing raised without a dad or a mother, is not the end in and of itself. People with stable two parent families aren't always superior mentally, without exceptions. Just as all drug users aren't brain damaged, all drinkers aren't alcoholics, and all child abuse victims aren't mentally ill. "Some but not all", is a phrase that can be used quite often when discussing things such as this article.
Nevertheless, what can be proven and predicted through experiment and the interpretation of results oftentimes does hold true; if only for reasons outside of the experiments themselves. Strong male authority figures who are fair disciplinarians make a big difference in the way a lot of adults turn out. Smart choices generally make smarter people. Early childhood cognitive/neurological development would seem to have little to do with this fact in a direct sense. I am not sure how much of the study would apply to someone like myself: a late blooming left hand dominant individual. I don't think left-handers develop quite the same way as many right-handers do. But, that might be difficult to divine from the rhetoric on the subject.
Actually the idea of bands of humans bringing up infants is only novel to modern, western minds. I vividly recall discussing a woman who had discharged herself from a maternity ward the day after giving birth, to go home to look after her other four children, in a group which had some Asian members - they were very surprised that this could happen - they described how, in their cultures, a mother was expected to rest fro the first 20/30/40 days (in India/China/Sri Lanka - but I think the order is wrong) after the birth to recover from her pregancy and birth by the whole community, who cared for the baya, presenting it to the mother for feeding when she was ready,
Reply | Report Abuse | Link to thisInteresting article, I think gunslinger hit a bullseye, while others have hit other bullseyes, sociology vs. biology, etc.
Reply | Report Abuse | Link to thisIn this day and age, there are many ways of getting a child, the good old one, sex, adoption (of newborns or later), in vitro fertilization, surrogate mothers with one or both parents genes, both of the last two being raised by either a couple or a single mom, possibly I missed a combination or two.
It would be interesting to study, whether the brain changes in father and offspring depends on the male being the biological father, or "just" his being there at birth and participating in the rearing, in different combinations.
I don't understand some of the comments criticising this article. I found it interesting, warm hearted and compelling.
Reply | Report Abuse | Link to thisIn no way did this article, on my reading, attempt to deny any of the impacts of social conditioning on parental roles - nor did it really touch on cultural norms and how they may vary from society to society or over history.
All it says is that there is evidence for a very real physical bond between father and son that, if allowed to develop, establishes important real brain changes in both that appear to aid in successful development of the child. It doesn't say that without such a bond the child is doomed - only that it is better if it is allowed to happen.
I don't see how there can be any argument that it is better if the biological father (assuming they are not abusive or dysfunctional) forms a strong bond with their child.
That isn't an argument against other forms of child rearing - be they single parent, same gender couplings or broader "village" style support - clearly there is evidence that these can be successful too. But it is an argument for recognising and nurturing the role of the father in circumstances that prevail most commonly in our own society and in the natural world where species form similar pair bonds to humans
Oops - I should have said between father and daugher too! My bad - I have two children - one of each gender - and I'm lucky to be close to both
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