A. Neurotransmitters are important.  Where do they come from?

• Mom
• Diet
• Inhalation
• Absorption
• The miraculous "balancing" done by metabolism... (e.g., excretion).
• Notice that children don't have a well developed "blood-brain barrier."
• e.g., environmental lead sneaks in as do Hg, PCBs, ...
• Notice that we are "historical" -- if you "lose something" early you may never catch up...
• The metaphor of Waddington's Cliff...  A child is a bouncy rubber ball finding its way down a rugged steep cliff on its way to the ocean...  It starts the journey at one point.  The ruts and the wind determine the route and the final location.

• Tobacco kills big time.  Do you care?  Would you care if the "costs" were assigned to your loved ones?  Aren't they?
• Each pack costs $20+
• Alcohol costs $99 billion/year in USA while other drugs cost $67b/y.
• Industrial Solvents Intoxicate as well.
• Environmental Lead has reduced the abilities of ALL of US!!
• "There is no control group anymore."
• The IQ of kids is lowered by exposure to Lead (show the IQ curve)
• And the impact depends on "Social Class."
• We KNEW this in 1840!
• The Paint Industry and The Auto Industry Covered Up
• Lead isn't the only problem:
• Pesticides are in the same chemical family as NERVE GAS!!!
• PCBs bioaccumulate since they are not biodegraded.
• The list is very, very long...

• Toxicants generally don't "hurt."  I wish they did.
• We can't measure "POTENTIAL," just "ACTUAL" abilities.
• Aside on Psychological testing:
• Here's something that Lead impairs: Reaction Time.
• Psychological Tests show how your scores ranks within those of the NORMING GROUP.
• Show the "BELL SHAPED CURVE" that underlies test scores.
• Notice that this way of expressing your score is not evil even though it is often misused.
• Notice that this way of expressing your score DOES NOT show HOW WELL you PERFORMED...
• The SAT is a test like this -- used to predict College Grades...  Is it working for you?
• It is made up of many questions (tests like Reaction Time).
• Questions are formed into "scales": Verbal, Math, ...
• The IQ test is a test like this too... also often having "scales."
• Personality tests are tests like this...
• All Psychological Tests are like this...
• Scores ARE based on your performance.  Performance is influenced by  both genes and experience.  Tests never tell where your scores come from.  Just their "location" within the distribution of scores.
• Psychological Tests are not evil -- they just need to be understood.

• I have focused on CHEMICALS that a child absorbs and incorporates.
• Yet, a child accumulates many things from their experiences...
• In a sense, we are all "falling down the same cliff"...
• Yet each person has a unique starting place
• And many things that influence their path.
• The Developmental Perspective acknowledges all these life-long factors...