Category Archives: BodyMind

Family Institute Course: Born Into, Born With

Today we looked at a number of the realities present at birth.  These are the factors — both within and around the individual — that give rise to individual differences among us.

Think of life as a journey.

All of us, embarking on the journey, come to terms with the human condition — ineluctable dimensions of life in this world that we share in common.  We talked about some of those dimensions: that we are embodied, that we have an inner world, and that our nature is social.  Another feature of the human condition is that in our lives, from beginning to end, we are involved with intentionality and goal-seeking, and the creation of meaning that gives shape and substance to our exercise of self-agency.

In addition to the commonalities, we have individual differences in where we start our journey, and who we are as we begin.

It’s easy to see that we all start from different places, and that our journey will be influenced by our social ecology: we’re born into different historical times and geopolitical locations, different social/cultural/sub-cultural contexts, different local communities, and different families of origin that include different individuals with whom we will form unique relationships.

Bronfenbrenner’s Social-Ecological Model of Development
Center for Child & Community Development
Southern Methodist University, Dallas, TX

At the same time, we’re born with a set of characteristics reflecting  the history of our prenatal (gestational) and perinatal (birth process) experiences, and our genetic endowment.

For humans, genes don’t dictate behavior in any direct way.  Some species are born pre-wired with the skills they’ll need to survive; think fruit flies, or baby turtles.  Some are born with pre-wiring that is “unlocked” and elaborated by some form of learning early in life.  Primates, many mammals, and indeed all social species fall into this category.  Humans are the species whose development is most dependent on a lengthy period of learning, training, and apprenticeship that turns them from novices to advanced beginners in the journey of life.  In the eloquent words of Gary Marcus,

Innateness is about the extent to which the brain is prewired, plasticity about the extent to which it can be rewired. Some organisms may be good at one but not the other: chimpanzees, for example, may have intricate innate wiring yet, in comparison to humans, relatively few mechanisms for rewiring their brains. Other organisms may be lousy at both: C. elegans worms have limited initial structure, and relatively little in the way of techniques for rewiring their nervous system on the basis of experience. And some organisms, such as humans, are well-endowed in both respects, with enormously intricate initial architecture and fantastically powerful and flexible means for rewiring in the face of experience.  (2004, pg. 10)

Almost all the traits of interest in human development are polygenic in origin — dependent on the joint operation of many different elements of the genetic code — and genes’ influence is probabilistic rather than deterministic.  The expression of our genetic endowment is the outcome of a complex series of transactions between the individual and the world, or G X E: genes interacting with environment.  The study of this process is called behavioral genetics.  These sites will introduce you to key concepts in the field.

One more step, and we’ll be ready to look at temperament, the relatively enduring set of characteristics with which we begin life’s journey.  Variations in temperament, present at birth, reflect the influence of genetic, prenatal, and perinatal factors, and represent individual differences in how each nervous system responds to environmental stimulation.  Genetic sources of temperament exert their influence by shaping important properties of the nervous system — the “initial architecture” to which Gary Marcus refers — as described in this brief overview.

So when we look at dimensions of temperament described by researchers — whether nine dimensions, three, or five — we’re seeing the individual’s nervous system in action, with its specific, characteristic patterns of reactivity.  There will be some degree of change in those patterns as a result of experience, since the nervous system is plastic; yet since a person’s temperament both affects the environment and shapes the person’s experience of environmental events and conditions, characteristic patterns may persist over a range of experiences.  Wachs (2006) gives a detailed analysis of this interaction, and Kagan (2009) discusses stability and change in one temperament dimension that has been the focus of his research.

A recent analysis depicts the mutual influences of genetic endowment, nervous system reactivity, environmental events and conditions, and behavior.  No simple one-way lines of causality here!

Hyde, Bodgan, & Hariri (2011). Understanding risk for psychopathology through imaging gene-environment interactions. Tr.Cog.Sci., 25, 423.

Now let’s look at one treatment of temperament: the description offered by Stella Chess and Alexander Thomas, among the principal investigators of the New York Longitudinal Study in the 1950s.  In class we used materials from a website designed to educate parents about child temperament; the specific handout we began to review was called “Tips for Handling Problematic Temperament Traits.”

At our next session, we’ll spend some time with the handout, and then progress to our discussion of resilience in human development.  More on that later!

And between now and then   .   .   .   shanah tovah u’metukah!

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Filed under BodyMind, Individual Differences, Overview

Jet Lag

It’s real.

Jet Lag Sends Brain Ahead A Time Zone, Leaves Kidneys In Another

Yup.

Who knew that every organ in our body operates on its own internal time clock, with the totality of the body’s organ systems synchronized by a “master pacemaker” in the anterior hypothalamus, linking our internal rhythms with events and conditions in the surrounding environment?

When this complex orchestration is working well, we don’t even notice.  When it’s disrupted — in jet lag, shift work, and some illnesses — the inside and the outside don’t match up, and we’re out of sync within ourselves, as well.   Literally, according to Gregor Eichele at the Max Planck Institute, “the clocks associated with individual organs in the body adapt to the new time at different speeds.  As a result, the body’s physiological processes are no longer coordinated.”

Our bodies participate in an ongoing dance with the rest of the world.  Some cells (sensory receptors) bring new information about what’s happening outside, and all cells communicate back and forth among and within themselves, continually.  Not only neurons, but heart cells, hair cells, red blood cells — every tiny part of us is busily sending and receiving signals, organizing itself internally and integrating with everything around it.  We become entrained with the larger rhythms that shape our world, whether we mean to or not.

Circadian rhythm” is the orderly sequence through which our body temperature, metabolism, and states of consciousness fluctuate throughout each 24-hour period, in sync with the coming and going of sunlight in our immediate environment.  The circadian clock coordinates all the bodily processes that maintain vitality, health, growth, and capability for reproduction.

Graphic from Xiaoyong Yang (2010), A wheel of time: the circadian clock, nuclear receptors, and physiologyGenes & Development, 24, 741-747.

You can map out your body’s predictable daily ups and downs with this online “Daily Rhythm Test” from the BBC.  (Patterns of energy abundance throughout the day vary for the morning people and the evening people among us.)  And you can learn more about cell signalling, the technical term for communication within and between cells, in an online tutorial available here.

BTW, we’re not the only ones.  All living beings — plants, animals of the land, sea, and air, and even Neurospora crassa (bread mold!) — share a “master clock” mechanism by which they tune into the daily cycles of time.  Like us, they align their rhythms with the larger processes in which they are embedded, maintaining the dynamic homeostasis that supports life.

It’s this intricate system that’s disrupted when we cross time zones: our body is still expecting the sun to rise and set when it did in the place of origin, and has to adjust to the timing that’s in effect in the place of arrival.  Information about incident light enters through the eyes, and all our organs scramble to synchronize with the new schedule, and with each other.  The problem is that some (such as the adrenal glands) are at the front of the line, while others lag far behind.  Get with the program, guys!

There now.  Even jet lag takes a back seat to contemplating the wonders of creation.

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Filed under BodyMind, Entrainment, States of Consciousness