Biblical principles regarding behavior:
--We are to examine our own behavior, confess our sins, and repent of them.
--We are to encourage the spiritually weak who are struggling with temptation.
--We are to minister to the sick, and try to heal them if possible.
--We are to value the variety of non-sinful differences in other people, since these may reflect God's special gifts to them and to the church.

How society typically classifies behavior:
Free choice: The behavior was freely chosen by the individual.
Implication: Hold people responsible for bad behavior, punish them.
Illness: The behavior was caused by a medical condition.
Implication: Treat them with drugs, therapy, and other medical interventions.
Natural: The behavior falls within the variability of how normal, healthy people behave.
Implication: As long as they're not hurting anyone else, leave them alone.

Biological factors which influence behavioral choice:
Neurodegenerative disease or brain injury. (e.g. brain tumor, Alzheimer's disease, Tourette's syndrome.)
Can alter behavior and in some cases personality. Changes can occur slowly or suddenly.
Psychological trauma. (e.g. being abused as a child.)
Can have long-lasting affects in the brain which play a role in later behavior.
Genetic predispositions. (e.g. some forms of alcoholism, some forms of obesity.)
Particular genes affect brain functioning to predispose people towards certain behaviors.
Evolutionary psychology. (e.g. hypothesis linking social status, serotonin levels, and use of violence.)
Attempts to understand human behavior patterns as strategies for survival and reproductive success in a complex social hierarchy.
Brain biochemistry. (e.g. some forms of clinical depression.)
Behavior and personality can be profoundly influenced by neurotransmitter levels and by drugs which alter those levels.

Our behavior, attitude, and personality are very much subject to our conscious, deliberate choices in our everyday lives. But we are learning that our behavior, attitude, and personality are also subject to biological factors beyond our conscious control.

Claim: If we identify biological factors influencing a behavior ==> then we shouldn't hold people responsible for it.
Version 1: Human behavior is completely deterministic. This claim is a gross extrapolation of current data and ignores the data of the meaningful choices we experience in our everyday lives.
Version 2: Compartmentalizing behavior. It is too simplistic to categorize behavior as freely chosen or determined by biological factors. Whatever our biological condition (except in the most extreme cases), we can make deliberate choices to either succumb to, or to overcome, behaviors to which we might have a predisposition. (e.g. overcoming alcoholism through deliberate choices.) Biological factors may make this easier or more difficult.

Holistic view of behavior: Our physical, neurological, psychological, emotional, and spiritual aspects form a unified whole which influence each other in ways we are only beginning to learn about scientifically. For some individuals, the first important step to healing an emotional and spiritual crisis will be a medical treatment (taking a drug, or simply getting the right food, exercise, and rest). For other individuals, such medical treatments would only mask problems which must be addressed, first of all, through counseling, prayer, repentance, and spiritual disciplines. The right strategy of medical, psychological, social, and spiritual approaches must be tailored to each individual's situation, using our best judgment about which to emphasize, and in which order.

"Taking" responsibility: We acknowledge that factors beyond our control were, to a greater or lesser extent, responsible for our current unpleasant situation -- whether that is drug addiction, depression, a quick temper, or a hateful or prideful attitude. Now that we are aware of those factors, we can do something about them. This knowledge increases our responsibility for our behavior, rather than decreasing responsibility.

Brain biochemistry and everyday life: Activities like eating too much junk food, drinking caffeine, or simply getting sufficient food, rest, and exercise can influence our behavior, our attitudes, our temper, our patience, and how well we concentrate during spiritual disciplines. "Physical" activities like eating and exercising have spiritual consequences.

What about "sin"? Christian theology refers to "sin" both as specific choices/actions and as our entire sinful condition ("original sin"). The Son of God came to earth to overcome both of these problems and so restore us to God. Sin does not consist only of nasty behavior towards others. Sin is turning away from God.

What about the "soul"?

Claim: Brain activity can account for everything we think our "mind" is doing ==> "proves" that there is no soul and no life after death.
--The scientific claim is premature.
--Christian beliefs about the soul do not rely on a "ghost in the machine" picture of its activity.
Dualist view of human nature: we have immaterial souls united with a material body.
Monist view of human nature: we are all of a single unified nature.
--Most ancient and medieval philosophers and theologians favored dualism. Modern neuroscience, as it learns more about brain activity correlates for mental activities, seems to be favoring monism.
--Both monism and dualism can be pictured in ways compatible, and incompatible, with Christian theology. Biblical revelation does not clearly spell out which is the better picture of human nature.
--Christian dualism would say that our souls are created (not existing from eternity). Our material bodies are part of good creation (not a "trap" for the soul). In the resurrection from death, our immaterial souls are united with a new suitable body.
--Christian monism would say that God created our remarkable brains such that its functioning allows us to be intelligent, self-aware beings to whom God can relate personally and whom God can hold accountable. In the resurrection from death, our bodies will be new and transformed, but with some appropriate continuity of "self" with our old bodies.
--Our continued existence, both in this life and in life after death, depends upon God's constant sustaining grace. However we picture the body and the soul, we ultimately rely on God's grace and the promise of the resurrection.

Suggested non-technical readings about the brain and consciousness:
"The Problem of Consciousness" by Francis Crick and Christof Koch, in Scientific American 1997 special issue "Mysteries of the Mind" p.19-26.
"The Puzzle of Conscious Experience" by David Chalmers. ibid p.30-37.

Suggested non-technical readings about biochemistry and behavior:
"Seeking the Criminal Element" by W. Wayt Biggs. ibid p.102-110.
"The Biology of Violence" by Robert Wright, in The New Yorker, March 13, 1995, p.68-77
"One Pill Makes You Larger, One Pill Makes You Small" by Sharon Begley, in Newsweek February 7, 1994, p.37-40.
Listening to Prozac by Peter D. Kramer. (Viking, New York, 1993).
The Man Who Mistook His Wife For a Hat and Other Clinical Tales by Oliver W. Sacks. (Harper, New York, 1990).

Christian perspective on neuroscience:
The Open Mind by Donald M. Mackay. (Intervarsity Press, Leicester, England, 1988). Chapters 1 and 5.
"Nice People or New Men" in Mere Christianity by C.S. Lewis. (Macmillan, New York, 1984).