In the human brain the left hemisphere controls language, the dexterity of the right hand,
the ability to classify, and routine behavior in general. The right hemisphere specializes in reacting to emergencies, organizing items spatially, recognizing faces and processing emotions.
Image: Photoillustration by TWIST CREATIVE; MedicalRF.com Corbis (brain); Medioimages Getty Images (calculator); Joerg Steffens Corbis (faces); Westend61 Corbis (woman smiling); Dougal Waters Getty Images (ballerina); Mike Kemp Getty Images (rattlesnake); C Squared Studios Getty Images (palette); Vladimir Godnik Getty Images (paintbrushes); Carrie Boretz Corbis (girls whispering); Robert Llewellyn Corbis (calipers)
In Brief
- The authors have proposed that the specialization of the brain’s two hemispheres was already in place when vertebrates arose 500 million years ago.
- The left hemisphere originally seems to have focused in general on controlling well-established patterns of behavior; the right specialized in detecting and responding to unexpected stimuli.
- Both speech and right-handedness may have evolved from a specialization for the control of routine behavior.
- Face recognition and the processing of spatial relations may trace their heritage to a need to sense predators quickly.
The left hemisphere of the human brain controls language, arguably our greatest mental attribute. It also controls the remarkable dexterity of the human right hand. The right hemisphere is dominant in the control of, among other things, our sense of how objects interrelate in space. Forty years ago the broad scientific consensus held that, in addition to language, right-handedness and the specialization of just one side of the brain for processing spatial relations occur in humans alone. Other animals, it was thought, have no hemispheric specializations of any kind.
Those beliefs fit well with the view that people have a special evolutionary status. Biologists and behavioral scientists generally agreed that right-handedness evolved in our hominid ancestors as they learned to build and use tools, about 2.5 million years ago. Right-handedness was also thought to underlie speech. Perhaps, as the story went, the left hemisphere simply added sign language to its repertoire of skilled manual actions and then converted it to speech. Or perhaps the left brain’s capacity for controlling manual action extended to controlling the vocal apparatus for speech. In either case, speech and language evolved from a relatively recent manual talent for toolmaking. The right hemisphere, meanwhile, was thought to have evolved by default into a center for processing spatial relations, after the left hemisphere became specialized for handedness.
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49 Comments
Add CommentE. O. Wilson described the insect brain as a thermostat. That would seem to equate with the non-linear, parallel processor of the right brain. The serial processor of the left hemisphere would seem to be a clock, in that it corresponds to the linear cause and effect sequencing of time. While the brain, as a manifest physical object, goes from past events to future ones, the mind is a record of those events, which once created, are replaced and then recede into the past. We think of time as a dimension along which events exist, but these events are an emergent effect of elementary activity. So it would seem time is an emergent effect of motion and it is the events going through the physical present, from future potential to past circumstance. The earth doesn't travel the fourth dimension from yesterday to tomorrow, rather tomorrow becomes yesterday because the earth rotates. Thus time is an effect of motion, like temperature and so it would make sense that our brains process these two elementary effects.
Reply | Report Abuse | Link to thisI would like to hear other people thoughts regarding the evolutionary reasons
Reply | Report Abuse | Link to thiswhy in humans and other vertebrates, nerves to one side of the body
are linked to the opposite side hemisphere.
My hypothesis is:
IF on our vertebrate ancestor the right side of the CNS controlled the
right side side of the body - that would allow selfish behavior in
both halves of the brain. If a predator would attack from the left,
the right brain could just "accept" the loss of part of the left body,
specially if the left could regenerate again. That selfish behavior
and lack of cooperation between both sides of the brain would not
allow the development of the "two-sided advantage"("a lateralized
brain is more efficient") described in your article.
When you "cross" the brain, cooperation appears - I protect your side
of the body and you protect my side. :-)
It is similar how in democracy the separation of powers with
cross-checks among the different sides of power is a model for
governance.
I am not sure either when this crossed brain appeared on nature - does
it happen only in vertebrates?
Paulo Andre
just wanted to register, while i'm here i have a thought About every 11,000 years the north and south poles flip. Just on the polarity switch does that effect the brain?
Reply | Report Abuse | Link to this"New systems or add-on anatomical structures per future queries of physiological blue prints are not trackable." Unknown
Reply | Report Abuse | Link to thisThank you for the information. Understanding the functions of each side of the brain is important. But comprehending the emotional aspects of the brain gives us insights into how brain the works.
Reply | Report Abuse | Link to thisSeveral of those emotions include; empathy, managing feelings, self-regulation, boundaries, and caring. Another part of understanding the brain is intuition which includes the gathering of information by the brain to make decisions.
Correct me if I am wrong: don't each of the retinas broadcast information to both hemispheres? Doesn't the visual data from only one eye open still end up in both hemispheres - because that's what it looks like in my old textbook.
Reply | Report Abuse | Link to thisGood grief. Six pages of "Just so."
Reply | Report Abuse | Link to thisAbout 15% (?) of the population is left-handed, left-eyed, and presumably right brained, inlcuding me. I use my right hand to do the tasks requiring repetitive movement, large muscle coordination, and throw a ball (poorly). I am artistic, creative, very visual (including seeing how mechanical things work), mathematically and electronically challenged, and language and verbally adept (except when a fast comeback to a verbal attack would be an advantage). This article did not mention much about what is known about the evolution of we right-brainers and the ambidextrous.
Reply | Report Abuse | Link to thisfrgough - what a great response !!! Thanks from a leftie.
Reply | Report Abuse | Link to thisGod created earth in six days... we did not evolve into this. We were made like this.
Reply | Report Abuse | Link to thisBarbara, just to respond, there isn't really such a thing as being left or right brained, left or right handed yes, but we are not specialized with each one of us having a different hemisphere dominating and determining what our strengths and weaknesses are. That has to do more with nurture, what you have experience doing. And maybe a little genetics thrown in there.
Reply | Report Abuse | Link to thisNote I am not a professional saying this, but I did spent the last year and a half studying lateralization in manatees and recently defended my thesis on the topic of lateralization.
Squish, yes each eye sends what it sees to the visual cortex of both hemispheres of the brain, but it depends on which side of the visual field it is! So, the right eye receives information from the right side of us reflected onto the left retina of the right eye, and the information coming to our eye from the left side of us is reflected onto the right side of our right eye retina. The nerves from the left side of the right eye retina travel to the left hemisphere and the nerves connecting to the right side travel to the right hemisphere. It is a similar concept in the left eye. In this way, the information from the right side of us, our Right Visual Field (RVF or RVH in reference to hemifield) is transmitted to the left hemisphere, and the information from our left visual field is transmitted to the right hemisphere.
Reply | Report Abuse | Link to thisHowever, in this article they are referring to birds, amphibians and fishes when talking about eye preferences, and their eyes are different than ours. These animals have complete decussation of the nerves at the optic chiasm, meaning all of the nerves from the right eye go only to the left hemisphere and vice versa. This works because they have laterally placed eyes, so the right eye only sees the RVF and left eye only sees the LVF. Human eyes, however, are pancaked on our faces and see a bit of each visual field.
Hope this clears things up for you!
Jordan, I understand you have different beliefs than those many of us that do believe strongly in the evidence which supports evolution, but if you do believe so strongly that evolution isn't the real deal, then why exactly are you reading and commenting on Scientific American, a publication which includes articles that mostly explicitly support evolution?
Reply | Report Abuse | Link to thisI just don't think you will get a whole lot of support on here spouting such slander (in the minds of scientists anyway).
I have to Westies that are littermates. When I was teaching them to shake, when they were 3 months old, one of them refused to shake with his right paw. He would only pick up his left one, despite my attempts otherwise.
Reply | Report Abuse | Link to thisHe will only shake with his left front paw.
Being left-handed myself, I was thrilled to discover, quite by accident, that one of my 'boys' was a leftie, too!
That was supposed to be 'two Westies'!!!
Reply | Report Abuse | Link to thisYou may be interested to know that they have developed a specific test just to test for paw preferences in dogs, well a few tests actually. There is a kong test, in which you can fill a kong with their developed food, or i would say use peanut butter and give it to your dog! Then you just watch and record which paw he or she uses! There is also a tape test, you can just stick a piece of tape on your dog's nose and see which paw he or she uses to wipe it off, too funny!
Reply | Report Abuse | Link to thisboxer-left forward defense(react),right attack(planning)
Reply | Report Abuse | Link to thisboxer-lefthand defense(react), righthand offense(planning)
Reply | Report Abuse | Link to thisStrange !! I was just reading this paper "dipoleneurology" on the formation of brain hemispheres as being an expression of a dipole structure.
Reply | Report Abuse | Link to thishttp://www.dipoleneurology.org.uk/__Pages/PDF/Dipole%20Neurology%20preprint%20jan%202009.pdf
It looks well researched but a bit beyond me. IF their theory is true then its consistent with this finding that hemispheres go right back to the origins of the nervous system. The problem is its very strange percieving us as walking talking dipoles !!
Why is Jordan reading scientific American? He should stick to his Bible.
Reply | Report Abuse | Link to thisI enjoyed the "Origins of the Left and Right Brain" story in the July '09 issue. I struggled with one line of evidence. My understanding of eye wiring is that the left half of the left retina goes to the left side of the brain and the right side of the left retina goes to the right side. The right eye is of course similarly wired. It makes sense to me that different visual fields would trigger different brain hemispheres preferentially, but covering or impeding one eye should not work that way since each eye is wired to both hemispheres. Am I missing something?
Reply | Report Abuse | Link to thisThese three professors, although supposed specialists in their fields, are, IMHO, not thinking too well - perhaps too 'traditional' in perspective, they try to present 'difference' (their pet hypothesis) but still within a context of 'sameness' (scientific community) and so do not break symmetry, only distort it. For more on this see the mindbrain list post message 17294:
Reply | Report Abuse | Link to thishttp://tech.groups.yahoo.com/group/MindBrain/messages/17294
TO some on this comments thread - the biases to left/right are statistical and so cover the general population allowing for variations that include 'swapping' of sides as well as lack in differentiation of 'sidedness'.
Reply | Report Abuse | Link to thisThe associations made in the article lack awareness of the general features of the lateralisations - e,g, language is NOT 'left brained', SEQUENCING is 'left brained'. The WHOLE brain deals with language and we can trace that down to the basic neuron. IT is LOCAL context that introduces biases to information processing and so 'small world network' brains from the regular network of potential connections that come out of our genetics as a neuron-dependent species.
To clarify a bit more, the overall, generic focus, of brain information processing is coverage of anti-symmetry (parts/aspects)/asymmetry(mediations)/symmetry(whole)
Reply | Report Abuse | Link to thisANYTHING will be mapped to those distinctions and the dynamics across them. As a species that has developed in an asymmetric, theromodynamic, universe we have followed the 'best fit' and that is to conserve energy and so developed a symmetric form (determinism as genetics, social dynamics etc). As such characteristics of 'right brain' reflect symmetry biases over characteristics of 'left brain' reflects anti-symmetry biases and oscillations across both reflect mediation - the asymmetry of our consciousness. LOCAL CONTEXT will then elicit 'biases' to give us 'small world network' brains.
I think these authors are guilty of post-hoc Darwinism. Having discovered a difference between occurrence of functions in the two hemispheres, they search for reasons why it might have been evolutionarily advantageous. This is pure speculation, and adding game theoretic results which assume an advantage doesn't prove anything. About the only ad hominem rationalization they don't indulge in is calling left-handers sinister; they congratulate right-handers for their dexterity. They don't address the different types of left-handedness (reverse physiology v. transposition of function) nor explain why left-handed could persist in 10-15% of the population if it were evolutionarily disfavored. Outside of showing that a chick can't walk and chew gum at the same time, they show no evidence that the time to carry nerve signals across the corpus callosum makes a significant difference in response time. Nor do they explain peoples' ability to play the piano or harp or wind instruments with both hands, or ambidextrousness. As earlier commenters have pointed out, the wiring of the visual system is different in birds and humans, so these interspecies comparisons do not necessarily prove anything. The evolutionary evidence is that neither whales nor humans have been subjected to any challenge where jawed- or handed-ness has been critical to survival until reproduction.
Reply | Report Abuse | Link to thisTo barbara Yantz - Yes I am in the same situation as you - left handed and occasionally ambi-dexterous from living in a right handed world. I too am " artistic, creative, very visual (including seeing how mechanical things work), mathematically and electronically challenged, and language and verbally adept (except when a fast comeback to a verbal attack would be an advantage)." to learn how we fit in with this theory should be adressed at some point in time.
Reply | Report Abuse | Link to thisI am left handed mostly and occasionally ambidextrous from necessity. It is interesting that Barabara Yantz and myself are similar: "artistic, creative, very visual (including seeing how mechanical things work), mathematically and electronically challenged". My father and daughter are both lefties but do not share these traits. I would like to read futher studies by the author on how the 15% of not right handed fit in to their theory.
Reply | Report Abuse | Link to thisIt's curious that we're taught to mount a horse from the left. This seems counter to the generality offered by the the snake-toad experiment in the article. Horses must be inconsistent with the left-right brain reaction because trial and error through the millenia of man's horseback riding would have discovered that mounting from the right resulted in a more pleasant experience than the start expected from a left-sided mount.
Reply | Report Abuse | Link to thisA truly fascinating article. I'm not a scientist, but I have been researching and writing a book about natural fiber rope for the past couple years. It's interesting that the most commonly used rope has been and continues to be right-hand laid -- fibers are first twisted "with the sun" as the sailor says, the resultant yarns are then twisted together in the opposite direction, and the finished rope is counter twisted once more "with the sun," into a right-hand lay. The question is, did the predominance of this pattern result from the left-brain function you talk about, or did primordial hands follow the natural twist put into fibers by the sun's path across the sky, or both? Russell Drumm
Reply | Report Abuse | Link to thisNice piece
Reply | Report Abuse | Link to thisI have a longer response, and in fact, and excerpt from my book on this subject, which may be inappropriate, but then may be worth consideration, but first, let me see if my comments can be added, as I am a subscrbier.
Reply | Report Abuse | Link to thisI found this article both interesting, thought provokoking, and hilarious in some aspects, in its lack of understanding of the larger picture of the psyche written about both psychologically and biologically, and which seems to ignore, or be unaware of the vast research on this subject. It would seem that this article would be better suited to the MIND issue, except that it deals so little with the mind, and more with biological aspects of the BRAIN, and therefore in many cases misses the point, which if I may, will attempt to explain.
Reply | Report Abuse | Link to thisNapoleon, that was asigned an IQ of 142 (obviously not enough to stay in business), claimed he was able to follow 4 conversations simultaneously. Anyone knows how to develop such multiattention abilities? Salut +
Reply | Report Abuse | Link to thisI am not clear of what you are accusing the authors .My understanding is that Darwinism itself is post-hoc in the sense that it constructs a theory of the past from what observations that the past left observable in the present.
Reply | Report Abuse | Link to thisThe species and lineages that met extinction without even leaving a trace of evidence are, forever lost to all available evidence gathering, hypotheses and Science.
No serious scientist/s would claim that his/her/their answer is complete in terms of a puzzle that is attacked.The farthest that an early-stage hypothesis can do is to fit most of what is known.Thus all your comments on the incompleteness of the explanation that the article is are valid contribution to the very process that science is.
I wish you didn't go and spoil it by calling something post-hoc that had no pretentions to the contrary!
This is truly a fascinating article and finally I found all my queries answered. Thank you very much. Im right-handed. However, just couple years ago I heard from my grandma that I was actually born to be left-handed. Til I grow up more, I found myself can use both and more and more go to logic and mathematical fields (which is much different from my previous study in the early years), thou I still write with right hand.
Reply | Report Abuse | Link to thisIn my life experience, it just has gone the way from right to the left. All the characters the authors mentioned are just what I have experiencing more recently. People usually find me strange as no one knows/thinks Im actually born to be left-handed. They always firstly perceive me right-handed, just like common people.
Now I have a few questions if they can be answered, I’d highly appreciate: 1) Why are there more other animals, say whales, of 1/5 “left-jawedness” while in humans less than 20%? Or the proportion is actually similar? 2) To what extent will it influence the individual development when one is forced to change the dominant hand for use with non-lateralisation? And 3) How much is the inheritance of being left-handed?
The anatomy of the optic nerve suggests that covering one eye does not cause input to only one brain hemisphere.
Reply | Report Abuse | Link to thisAt the optic chiasm half the impulses enter each optic tract, and so travel to both hemispheres.
The anatomy of the optic nerve suggests that covering one eye does not cause input to only one brain hemisphere.
Reply | Report Abuse | Link to thisAt the optic chiasm half the impulses enter each optic tract, and so travel to both hemispheres.
Paolo,
Reply | Report Abuse | Link to thisI was going to post an idea in general, but perhaps it's an answer to your question. My idea is to think about what happens when you face an enemy. Think of a boxing match. Most of your opponents are going to be right-handed and, therefore, strike from your left. The striking is a planned activity... left brain... but the reaction (parry, duck, etc.) is right brain. Thus, any sort of initial bias for a hemisphere to control a side is reinforced. Once you have a bias for Left Brain controls striking with the right hand, you get a reinforcement for Right Brain perceives the danger and tries to parry with the hand nearer the strike (the left). The cycle of better strikes and better parries leads to ever-stronger separation of function.
Squish -- note that this is consistent with the retinas feeding both hemispheres. (I wonder what implications this has for coverage in football or ultimate.)
So this is testable. You can look at predators... say a cheetah... to see if there's handedness in their strikes. And you can look at prey... gazelles... to see if there is handedness either in the way they look back to see their pursuer or in the direction they take for evasion. Anyone want to hang out on the savanna and watch?
The brain is not a muscle and should work effortlessly, that is, without conscious effort.A single glance at a long row of numbers should produce an instant sum.Only in rare instances is this and other 'so called' genius abilities observed.The spleen, liver, and other organs all function without conscious thinking-so should the undamaged brain in all humans.There is about 75 quadrillion brain cells in the average human head, but obviously the brain is not working as it should.This simple observation does not require a degree in science to understand that perhaps 'mental tensions' created in the ongoing conflict between the wordy left hemisphere and the right hemisphere is responsible for the state of arrested development that exists in humans.Science and educators teach to the left hemisphere that works in a step by step fashion which is an extremely laborious and slow method and a huge waste of the most awesome living computer in the known universe.Religious and secular governments have done a superb job of helping to keep mankind in a state of arrested development and a state of conflict and frustration."Is it not written in your laws that ye are as gods"? is a quote from the christian new testament supposedly spoken by the christ.Man is not a lowly sin ridden being, nor is man inherently bad.Behind all conflicts and wars is " The War of the Words", which happens to be the title of a book I am writing.-Jordan'
Reply | Report Abuse | Link to thisI am glad I checked back to see the kind of responses this article evoked, wow, from nonsense techno-geeks, to nonsense, so I will not feel so bad expressing my point of view, from personal experience: the childs psyche develops from the right brain, instinct, smell, taste, pattern recognition, to learn the mother, and the father, walk, bodily functions, and at some level, the psyche migrates to the left brain, where the speech, math, logic functions, begin to be developed, sit down and pay attention, reading writing and arithmetic, and gradually the right brain takes on a kind of hard drive function in relation to the CPU running mental software of the left brain, I think therefore I am, and forgets its origins in the right brain, and a hubris of consciousness begins to take place, as that which was lost, is lost forever, as the software of the left brain takes a dominant role, and the development route it has taken is forgotten. This developmental pattern would not seem accidental, or only human, but part of the larger evolutionary pattern, in the term phylogeny recapitulates ontogeny, in which the human organism, from creation through one cell to fetus, repeats many steps of the species through millions of years of development.
Reply | Report Abuse | Link to this“Consciousness is phylogenetically and ontogenetically a secondary phenomenon. It is time this obvious fact were grasped at last. Just as the body has an anatomical prehistory of millions of years, so also does the psychic system. And just as the human body today represents in each of its parts the result of this evolution, and everywhere still shows traces of its earlier stages—so the same may be said of the psyche. Consciousness began its evolution from an animal-like state which seems to us unconscious, and the same process of differentiation is repeated in every child. The psyche of the child in its preconscious state is anything but a ‘tabula rosa;’ it is already preformed in a recognizably individual way, and is moreover equipped will all the specifically human instincts, as well as with the a priori foundations of the higher functions…. On this complicated base, the ego arises. Throughout life the ego is sustained by this base…. Compared to it, even the external world is secondary, for what does the world matter if the endogenous impulse to grasp it and manipulate it is lacking? In the long run no conscious will can ever replace the life instinct….” C.G. Jung, “Memories, Dreams, Reflections,” 1961.
Reply | Report Abuse | Link to thisI think that the authors missed a great example of the responsibilities each side of the brain is to manage. One that almost every American could understand. It is as simple and as glorious as baseball. With which hand do most people throw (which is a relatively routine function)? The other potentially more threatening and dangerous function, that of catching a ball - a hurtling sphere of kinetic energy is assigned to the left hand.
Reply | Report Abuse | Link to thisIt is kind of neat realizing that the right hand handles all the delicate work but the left hand is just as necessary to survival. The only reason I bring this up is because sometimes, when I play video games... My thumbs argue with each other for territory and dominance.
It's OK Jordan. Clearly you were born yesterday. Fully grown and conspicuously uneducated.
Reply | Report Abuse | Link to this"Our hypothesis holds that the left hemisphere of the vertebrate brain was originally specialized for the control of well-established patterns of behavior under ordinary and familiar circumstances. In contrast, the right hemisphere, the primary seat of emotional arousal, was at first specialized for detecting and responding to unexpected stimuli in the environment."
Reply | Report Abuse | Link to thisThe authors really need to read some Julian Jaynes and his bicameral mind theory. His theory discusses lateralisation of brain function and corresponds quite nicely with the above sentence.
ok,
Reply | Report Abuse | Link to thishow did the split occur in the first place?
clearly one is two.
I managed to acquire a feel for the shifting of brain hemisphere usage. I had never done any research on the subject. I only knew that i could only focus out of one eye dominantly at a time, this got me thinking about separate hemispheres and how they could be consciously manipulated. I ended up in St. Vincents in Indy. for a week, they diagnosed me as Bipolar, manic, psychotic- possibly schizophrenic. I tried to explain the brain hemispheres thing they acted concerned, told me i was disillusion. Everything looked bold, vivid, and real for the first time in my life, like a high def TV compared to a poor quality. Time was slower based on how closely i observed my surroundings now i take lithium, they try to prescribe me something new all the time. If anyone knows of anyone who knows more about this, or has gone through this, or want to know how to go through this get a hold of me.
Reply | Report Abuse | Link to thisI have read an hypothesis that mankind underwent a polarity switch from being predominantly right-brain to becoming predominantly left-brain about 4000 - 4500 years ago. It is proposed that this came about as the result of the first appearance of writing in ancient Sumer which corresponds roughly to the time of the patriach Abram/Abraham who was himself a Sumerian born in Nippur. Prior to this, humans relied purely on memory to preserve and transmit information, particularly of an historical nature. Reading and writing brought about a greater usage of the left brain. We can probably see a model of this in our own life-cycle: very young children (pre-school) are predominantly right-brain, living in an imaginative world of make-believe. This begins to switch to left-brain as they begin to learn to read and write and goes through the difficult adolecent, or "teen" phase before becoming fully adult, left-brain led as is required by the modern technolical world.
Reply | Report Abuse | Link to thisMechanical Origin of Brain Asymmetry?
Reply | Report Abuse | Link to thisMacNeilage, Rogers and Vallortigara's article "Origins of the Left and Right Brain" presents a fascinating account of the nature and antiquity of functional differences between the left and right sides of the brain. Toward the end of their article, they ask, "Why have vertebrates favored the segregation of certain functions in one or the other half of the brain?" They suggest that differences between the segregated functions is, in itself, responsible for their segregation.
But the original cause of brain asymmetry might be more mechanical. The cerebral canal of vertebrates is lined with cilia (Wicht, H. & Lacalli, T. 2005. The Nervous System of Amphioxus: Structure, Development, and Evolutionary Significance. Canadian Journal of Zoology 83:122-150); and the cilia all beat in the same direction (Afzelius, B.A. 1976. A Human Syndrome Caused by Immotile Cilia. Science 193: 317-319). The cilia will thus present different fluid flow to the right side and the left of the brain as it develops in embryo. Differences of fluid flow have a profound effect on the viscera in the developing embryo (Afzelius, ibid) and might have some small effect on the developing brain, causing systematic differences between the two sides. Different functions might then have settled in the side most suitable to each.
William L. Abler
Department of Geology
The Field Museum.
Chicago, Illinois USA
wabler@fieldmuseum.org
I was surprised to see my "old" prof. in my magazine (Peter F. MacNeilage). Late for class as usual...actually I graduated years ago and still quote and saved his Psy337 course book (one of two, I thought worth saving). If you believe that the Triune Brain exists then the Limbic areas of the brain are thought to be the seat of our emotions such as flight or fight which no one can deny exists. These emotions have a biochemical bases along with neurotransmitter signals. For several scientists and lay people the idea that biochemicals are a basis for the emotions is ridiculous, but studies are showing that the different disciplines are overlapping to create a better picture of the evolution of human beings. There are still various academic barriers to over come the compartmentalization that prevents a unified whole, because of competition within various departments. Our past be it childhood experiences or evolutionary genetic mechanisms, hold one truth and that is that; whatever was preserved and used again and again over evolutionary time and across species was a universal survival strategy that helped us get to where we are today. Thank you Prof. MacNeilege for planting the seeds.
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