I’ve written previously about Maslow’s motivational hierarchy and how that relates to the eight stage evo-devo model. Most people are familiar with the 5 motivational basic needs/motives theory of Maslow, but are not aware that he had later revised it to include eight basic needs/ motives.

A recent paper by Krenrick et al also discusses the more popular 5 motivational scheme of Maslow and revamps the model by dropping self-actualization at the top and making room for 3 reproduction related motives -mate attraction, mate retention and parenting.  Regular readers will note that this is inline with the eight stages discussed during life-history theory based perspectives on this blog.

This new paper, which is available in full on authors website, is an important contribution and gets many things right, though I believe that safety need should trump physiological needs and that we need an eighth motive/need which would be related to finding meaning/purpose/transcendence .

Anyway, lets first see what a motivational system is:

Throughout this article, we have used the terms needs, motives, and goals somewhat loosely. Our view of motivational systems follows that of evolutionary theorists such as Plutchik (1980) and Scott (1980), with connections to the views of the original evolutionary psychologists such as William James (1890) and McDougall (1908) and to Carver and Scheier’s (1998) cybernetic view. On that view, any motivational system includes (a) a template for recognizing a particular class of relevant environmental threats or opportunities, (b) inner motivational/ physiological states designed to mobilize relevant resources, (c) cognitive decision rules designed to analyze trade-offs inherent in various prepotent responses, and (d) a set of responses designed to respond to threats or opportunities represented by the environmental inputs (i.e., to achieve adaptive goals).

To elaborate, and link with the ABCD model of psychology, desire/motivation forms a big sub-domain of psychology,m but motivation.desire can itself be broken into 1)Affective components (a template for recognizing a particular class of relevant environmental threats or opportunities) 2) Behavioral components ( a set of responses designed to respond to threats or opportunities represented by the environmental inputs) 3) Cognitive components (cognitive decision rules designed to analyze trade-offs inherent in various prepotent responses) and 4) Desire / motivation proper ( inner motivational/ physiological states designed to mobilize relevant resources).

The motivational system itself can be analyzed at different levels of analysis-Proximate reasons for a behavior and ultimate reasons for a behavior. The different levels of analysis include  evolutionary (ultimate), developmental, situational (proximate) and phenomenological.  These concern with the biological context, the ecological context , the cultural context and the personological context respective;y in which a (human) being functions.

Kenrcik et al consider the evolutionary ,  developmental and proximate mechanisms and level of analysis and use that to refine the Maslow’s ladder and that makes sense and is more or less inline with the eight stage model.

They also refer to Deci and Ryan and their intrinsic motives and I like to think of deci and Ryan motives as well as addition to that by Daniel pink as follows: 1) autonomy (from genes) 2)  mastery (over environment) 3) Belongingness (to culture) and 4) Purpose ( of self) – these intrinsic drives again related to biology, environment, culture and phenomenology.  Only the last level of analysis need make a reference to consciousness; all prior levels are/may be non-conscious.  I believe the lack of phenomenological level of analysis is limiting and perhaps the reason they miss the eight and highest motive.

The authors, apart from adding new motives of mate attraction. mate retention and parenting, also stress the point that these are overlapping/ can be activated simultaneously and do not necessarily follow developmental stages.

The original article itself is accompanied by commentaries and Kenrick himself maintains a blog and has written a  couple of blog posts related to this, so there are no excuses for not reading up more on this.

Douglas T. Kenrick,, Vladas Griskevicius,, Steven L. Neuberg, & Mark Schaller (2010). Renovating the Pyramid of Needs
Contemporary Extensions Built Upon Ancient Foundations Perspectives on Psychological science DOI: 10.1177/1745691610369469

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I’m no expert when it comes to complex questions like that related to neural development, but to my naive mind the major stages involved in neural development seem to follow the eight stages as outlined in in the eight stage evo-devo model.

The first stage is normally involved with the coming in being of a particular new form, in this case the birth and differentiation of a neuronal cell form its precursor stem cells.

The second stage typically involves motion and in this case refers to the migration of immature neurons from their birthplaces in the embryo to their final positions.

The third stage typically refers to connections and branching and in this case refers to the outgrowth of axons and dendrites from neurons.

The fourth stage is typically a social/ dormant sort of state and in this case refers to the guidance of the motile growth cone through the embryo towards postsynaptic partners.

The fifth stage typically is about achieving closure/integration/individuality and in this case refers to the generation of synapses between these axons and their postsynaptic partner.

After this the sixth ,seventh and eight stage refer to qualitatively different sort of development – that at synapse. We have synapse formation followed by changes in synaptic strength due to learning and memory; and finally the pruning of synapses to yield the best possible redundant neuronal system.

To me everything looks to follow the eight stage pattern; but does these major stages of neural development make sense to you too and seem to follow distinctive stage patterns?

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I’ve touched upon life history theory earlier, in an oblique fashion, while discussing evolutionary perspectives on personality.

Life History theory posits that an individual’s life efforts can be subsumed under two headings- somatic life efforts
and reproductive life efforts. The latter relates to selection due to being able to successfully replicate one-self; the former relates to the ability of an organism to survive and thus act as a vehicle for genes that can be replicated at a later date.  To elaborate more on the life history theory I quote:

Life History Theory is a mid-level theory from evolutionary biology that describes the strategic allocation of bioenergetic and material resources among different components of fitness (e.g., calories and nutrients devoted to growth vs. reproduction). Somatic Effort anchors one end of the first dimension of this trade-off whereas Reproductive Effort anchors the other. Somatic Effort refers to resources devoted to continued survival of the individual organism whereas Reproductive Effort refers to resources devoted to production of new organisms as vehicles for survival of the individual’s genes. The second dimension of this trade-oV further partitions Reproductive Effort. Mating Effort anchors one end of this continuum whereas Parental Effort and Nepotistic Effort jointly anchor the other. Mating Effort refers to resources devoted to obtaining and retaining sexual partners whereas Parental/Nepotistic Effort refers to resources devoted to enhancing the survival of existing offspring and other genetic relatives. Thus, a life-history strategy allocates an individual’s bioenergetic and material resources among the competing demands of survival and reproduction.

I break the somatic effort into five different functions:

1. Survival- each organism needs to survive and maintain its body integrity
2. Growth – each organism needs to consume energy and grow
3. Maintenance- each organism needs to maintain the body it accumulates as a result of previous efforts
4. Development- there is developmental unfolding and stages where different needs are met at different times
5. Differentiation/specialization- the organism makes efforts to create an environmental niche for itself

I agree with the authors that reproductive effort can be broken into 3 parts:

1. Mating effort- effort to find and retain a mate.
2. Parental effort- efforts devoted to nurture offspring
3. Nepotistic efforts- efforts devoted to helping close genetic kins.

The first three stages/efforts are related to energy balance while the next two are timing related. Finally the final three are efforts proper, thus completing the eight stage model.

The life history theory says that one has limited energy, time and efforts and needs to invest these limited resources wisely- between current and future reproduction; between quantity and quality of offspring; and between self and offspring.

Let me elaborate.

Current and future reproductive trade-offs can be conceptualized as a giant trade-off between somatic effort and reproductive effort. If I reproduce now, I do not invest in my growth, maintenance, survival etc and thus have lowered future chances of being able to survive and reproduce.  On the other hand if I do not reproduce now, I can invest the excess energy in somatic efforts- granting me future reproductive benefits, but incurring the opportunity cost of not reproducing now.

Quality and quantity of offspring trade-off can be conceptualized as how best to allocate resources, once I have decided to reproduce,  amongst a litter- the size of litter (no. of offsprings), the size of individual baby at birth and the quality or survivability of offspring at birth. All these are orthogonal to each other and involve trade-offs.

The final traditional trade-off is between self and offspring- the parent-offspring conflict. Given that I am reproducing some  offsprings now, what resources should I invest in them now,  such that my future reproductive costs are not sky-high and I can survive and reproduce later and invest in later offsprings too.  Here the two sexes have different incentives when a baby is gestating- for mother later offsprings will also be hers; for father later offsprings may not be his; thus father wants the baby to consume as many resources now as possible; while mother wants to spread resources more evenly- the genomic imprinting conflict theory.

Here it is instructive to pause and note the cost of reproductive (to mother)-

1. future survival (death in childbirth – for mammals important)
2. future energy capture (pregnancy, lactation and nursing resulting in less  loco mobility and foraging)
3. future reproduction (lowered fecundity as a result of prior child birth)

The avid reader will note that the three trade-offs refrred to above relate to the three stages of reproductiuve effort – mating (now/future), parenting (one/many child) and nepotism (future related babies/unrelated babies)

There do exist of course tradeoff between somatic and reproductive efforts and it has been shown time and gain that they are inversely related; however more interesting is the fact that somatic efforts themselves are multi-dimensional; thus forgoing reproduction may not simply lead to longer lifespan; it may just result in more growth and heavier bodies.

Also important to note the concept of r and K strategies.

Let us now look at some of the life history variables and again present them is a stage fashion, with special focus on r-K strategy and how these have antagonistic and opposite effects on variables under consideration:

1. Mortality rate (survival)- low in r , high in K
2. Body size (growth) -low in r, high in K
3. Metabolic activity related lifespan (maintenance)- low in r , high in K
4. Age of sexual maturity (developmental) – early in r, later in K
5. Age of first reproduction (differentiation/specialization)- early in r, later in K
6. duration of gestation/pregnancy (mating) – lesser in r, greater in K
7. no. and size of offspring in a litter (parenting)- more number and lesser size in r, smaller no. and bigger size in K
8. no. of reproductive events (nepotism)- semelparous or one reproductive event only in many r; iteraparous or multiple reproductive events in most K

Another way of parsing the data is to link these to developmental and evolutionary tasks and personality traits, as I had done earlier:

1. Foes: Survival
2. Food: Growth
3. Friends: Maintenance
4. Maturity: Development
5. Mate selection: specialization/differentiations (displays of creativity etc)
6. Mate retention: mating long term for future reproductive benefits
7. Parenting: parental efforts for ensuring well being of offsprings
8. Nepotism /altruism: favoring kin/ non-kin to ensure inclusive fitness

The last three are generally referred to as dilemmas of parental investment- balancing reproduction, well being of offsprings and inclusive fitness via nepotism with somatic or self fitness.

Its also instructive to note that many ecological variables affect the somatic as well as reproductive effort distribution (the r and K strategy are under ecological constraints to an extent).

For ex, changes in ecology like Mortality hazard (foe related) , food availability (food related) , density of con-specifics (friends related) , shortage of food during critical developmental window( maturity related) or differential habitats leading to different genetic variants (niche related) all lead to changes in these life history variables sometime affecting growth, sometimes reproduction, sometime lifespan etc etc. For eg caloric restriction may lead to increased lifespan etc etc

The above life history analysis was applied to organisms, but the same can be extended to brains and neurons-the following processes are involved in neuronal life history (neural Darwinism)

1. Neuronal survival
2. Neuronal growth
3. Neuronal maintenance
4. Neuronal developmental and
5. Neuronal specialization/differentiation.

In all of the above neurotropins or growth factors are instrumental and drive these processes. Whether or not this applies to neuronal level, but to organism level life history theory makes a lot of sense. What do you make of it and its fit with the 8 stage evolutionary theory?

Graf, M., Cellerino, A., & Englert, C. (2010). Gender Separation Increases Somatic Growth in Females but Does Not Affect Lifespan in Nothobranchius furzeri PLoS ONE, 5 (8) DOI: 10.1371/journal.pone.0011958
FIGUEREDO, A., VASQUEZ, G., BRUMBACH, B., SCHNEIDER, S., SEFCEK, J., TAL, I., HILL, D., WENNER, C., & JACOBS, W. (2006). Consilience and Life History Theory: From genes to brain to reproductive strategy Developmental Review, 26 (2), 243-275 DOI: 10.1016/j.dr.2006.02.002

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Autism is a spectrum disorder , better referred to as ASD, It has been known for some time that differences like autism are, multi-dimensional and not readily reducible to a single set of mechanisms or genetic causes. In the past we have discussed how the disorder may be related to structural differences in the brain like those due to minicolumnar differences.

A new study looked at structural differences in brains of people (adults) with ASD and instead of focusing piece-meal on one feature (like minicolumns) combined a multitude of structural features and used a multi-dimensional classification system to determine the accuracy and specificity of the structural differences to predict/aid in  diagnoses.

They came uyp with five dimensions- two based on volumetric measurements (surface area and cortical thickness) and the other three on geometric features (average convexity/concavity, mean radial curvature and metric distortion.  (the article is open access, so go read it to find what these mean:-) )

What they found was that cortical thickness was the strongest predictor and that predictive power was greater for Left hemisphere measures than for right hemisphere measures.

They also talk about what these measures may mean in terms of underlying neurons and substructures and I reproduce that here:

There is already evidence to suggest that several aspects of cerebral morphology are different in people with ASD—including both volumetric (i.e., cortical thickness, regional area) and geometric (i.e., cortical shape) features (Levitt et al., 2003; Nordahl et al., 2007); and that different morphological features may have different neuropathological and genetic underpinnings (Panizzon et al., 2009). For instance, cortical thickness is likely to reflect dendritic arborization (Huttenlocher, 1990), while cortical surface area has been linked to the number of minicolumns in the cortical layer (Rakic, 1988). Geometric features such as cortical folding pattern, on the other hand, may reflect an abnormal pattern of intrinsic as well as extrinsic connectivity (Van Essen, 1997). Thus, examining the relationship between such multiple cortical features could provide invaluable insights into the multifactorial etiology of ASD.

We know form previous work that all of the above (arborization, minicolumns, local and global connectivity) have been implicated in Autism. The important take-home for me from thi sstudy is the fact that all these are governed by possibly separate underlying genetic mechanisms and may thus be independent of each other. On its own variations in one dimension may not lead to full blown autism, but when variations in all five or more dimensions combine they may make one more susceptible to ASD diagnosis.

Remember we are only talking about structural change sin brains here; we haven’t even touched upon functional differences (default mode network?) and there is plethora of evidence that functional changes are also very important. Overall I believe the multi-dimensional nature of underlying structural and functional differences lend autism the spectrum property and also a continuum with normality. As always I would be eager to know how the SVM they used to classify Autistics fared when asked to classify Psychotics …did the pattern they see was reverse of Autism and inline with the Schizophrenia/psychosis as opposed to Autism theory?

Ecker, C., Marquand, A., Mourao-Miranda, J., Johnston, P., Daly, E., Brammer, M., Maltezos, S., Murphy, C., Robertson, D., Williams, S., & Murphy, D. (2010). Describing the Brain in Autism in Five Dimensions–Magnetic Resonance Imaging-Assisted Diagnosis of Autism Spectrum Disorder Using a Multiparameter Classification Approach Journal of Neuroscience, 30 (32), 10612-10623 DOI: 10.1523/JNEUROSCI.5413-09.2010

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I recently read ‘Neurodiversity: discovering the extraordinary gifts of Autism, ADHD, Dyslexia and other brain differences‘ (you can read a mini review here) by Dr. Thomas Armstrong and came away impressed. In the book Dr Armstrong makes a  strong case for viewing the traditional disabilities from a differences perspective and to focus on the different strengths and abilities of the neurodiverse people. A recurring theme of this blog has been that autism and schizophrenia/psychosis are opposites on a continuum model as proposed amongst others by Christopher Badcock and Beranard Crespi. Dr Armstrong touches on this model in his chapter on autism, though that not central to his theis .

Dr Armstrong, was kind enough to answer a few questions for the benefit of our readers and these are reproduced below:

[SG] You have written a wonderful book on neurodiversity. Could you explain in brief, for the benefit of our readers, why neurodiversity has become so important in today’s context and why the focus on neurodiversity now when the differences that underlie the neurodiverse spectrum themselves are age-old?

[TA] I think neurodiversity is, as I’ve suggested in my book, “a concept whose time has come” because of the disability culture we live in. Almost half of us will have mental disorders sometime during our lifetime according to the National Institute of Mental Health, and even more will have “shadow syndromes” or minor versions of those disorders. When we get to the point where virtually everyone is seen as having a mental disorder to one degree or another, I think it’s time that we shift paradigms and use a diversity model instead of a disability model to account for those differences.

[SG] How much does neurodiversity owe to the Autistic advocacy movement and whether those beginnings are productive or counterproductive when one wants to bring other differences like mood or anxiety differences in the fold and talk about them as well?

[TA] I believe that the autistic advocacy movement deserves a great deal of credit for coining and developing the idea of neurodiversity. It’s rather amazing that a group of people who are known for their non-social attributes have made this contribution to our social understanding of brain differences. My hope is that my book Neurodiversity will help to broaden the concept of neurodiversity to include a wider range of abilities/disabilities. As far as I can see from looking at many sites online, there is an openness in the autism community to expanding the definition of neurodiversity beyond simply autism and Asperger’s syndrome.

[SG] Positive Psychology shares some of the same concerns as that of the Neurodiverse movement- the focus on strengths and what works and skepticism about the disease and pathology model- yet why hasn’t, in your opinion neurodiversity become center stage like the positive psychology movement has? Is it because in neurodiversity we are swinging the pendulum too much to the other side and perhaps blinding ourselves to underlying pathologies by claiming everything as differences?

[TA] No, I think it has to do with the credibility of the leadership of the Positive Psychology movement – spearheaded by a former president of the American Psychological Association and other famous professors of psychology. It’s essentially a top-down movement, whereas neurodiversity seems to me to be a bottom-up or “grass roots” movement that is coming from the people who are actually themselves neurodiverse. I don’t think of the neurodiversity movement as saying “we’re all different so leave us alone” I believe that attention needs to be given to ameliorating the disability part of neurodiversity, even as we focus the spotlight on the abilities.

[SG] For the benefit of our readers, if you could highlight the differences between the dimensional and categorical model of pathologies/differences. I believe neurodviversity leans towards the dimensional (continuum ) model. What can DSM V learn form the findings you have discussed in the Neurodiversity book? is a dimensional model of pathology a better one as compared to the categorical one? a necessary evil? or can the DSM mentality be done away with altogether?

[TA] One of the eight principles that I discuss in my book Neurodiversity is that everyone exists along “continuums of competence” with respect to a range of human processes including sociability, literacy, intelligence(s), attention, mood, and so forth. This is very similar to the DSM-V’s embracing of a dimensional perspective, and to that extent, I think the DSM-V is moving in the right direction. The problem is that the DSM-V will be a high stakes publication, and if people are put on a continuum from normal to pathological, the fuzzy line where normal becomes pathological (and vice versa) becomes very important, and may determine whether a person will be labeled with a disorder, given a drug treatment, and perhaps even stigmatized as a result. There’s a danger that many so-called normal people will be added to the ranks of the mentally disordered. Also, what’s missing from the DSM (in all its versions) is any kind of discussion of the positive dimensions of each of the disability categories.

[SG] Just like DSM, positive psychologists have come up with a list of character strengths and virtues as for ex can be seen on VIA signature strength website. Do you think those lists are sufficiently inclusive and give equal weighting to the special abilities found in neurodiverse individuals?

[TA] I think the VIA-IS (or Values in Action Inventory of Strengths) is a positive contribution to our understanding of human personality. It would be good to see someone take this inventory and map it onto the various pathologies taken up in the DSM-V. Wedding the two manuals would be a definite step in the right direction.

[SG] How much yours and your fathers experience of depression has been a driving force in your passion for psychology and especially instrumental in your focusing energies on the neurodiverse people.

[TA] I think it’s been very much a contributory factor. Seeing how my father’s depression affected our family’s functioning while growing up, and how my own depression has shaped my adult life, has been extremely influential in leading me to the field of psychology, and in trying to find the silver lining beyond the dark cloud.

[SG] People who are on extremes of the neurodiverse spectrum face immense stigma in our society. Your chapter on neurodiverstity in classroom talks about inclusive classrooms as you believe special classrooms for special ed programs end up labeling children. How practical you think is the concept of a neurodiverse classroom, esp in developing countries like India. Is a special ed class, even if it ends up labeling a child, better than no intervention at all and traditional classroom education only?

[TA] In a system based on traditional classroom learning, I believe that special education programs outside of the traditional classroom have a place, especially if they are using cutting-edge techniques for helping kids with special needs. But as an educational reformer, I am always pressing educators to expand beyond traditional learning environments for all kids, and when we utilize teaching methods that are good for all kids, we end up helping kids with special needs in the process.

[SG] Niche construction appears to be one of the special focus of your book. would you support or recommended special reservations in jobs/academics for neurodiverse people who may do especially well in those particular niches? For ex. would you favor a legislation that mandated for reservation for autistic people in computer testing industry. I’m thinking of cultural diversity guidelines in colleges, should we have similar neurodiversity guidelines too?

[TA] Are you talking about affirmative action for neurodiverse people? If so, then I believe there might be some merit in exploring how this might work. ([SG] note: yes, I was indeed talking about affirmative action; in India we typically refer to the issue as that of reservations!)

[SG] How did the writing of Neurodiversity enrich you as an individual. wWat can readers hope to take away from the book?

[TA] I wrote Neurodiversity while in the midst of a major depressive episode. At times I could hear myself saying “why are you looking at the strengths of these disorders, for God’s sake, when you know that they’re hell to deal with?” But there was another part of me, an intuitive part I believe, that instinctively believed it was important for me to bring strengths into the discourse about mental disabilities. I hope that readers will see this book as a supplementary guide to all the other books on disabilities that focus on the negatives. It’s important that we see both sides of the issue. We are, after all, whole human beings, with a great deal of complexity and richness. I hope that readers will take away a sense of this richness in the diversity of minds that make up humanity.

I would like to thank Dr Armstrong for taking some time off for the interview and would recommended the readers to read up some of his books, many of which focus on the special abilities and aptitudes of the neurodiverse people.

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