Foundations of Psychology
How the mind works: consciousness, perception, and the basic architecture of human psychology.
What Is Psychology?
Psychology is the scientific study of mind and behavior. It examines:
- How we think, feel, and act
- Why we do what we do
- How the brain produces mental experience
- How we differ from each other
The Brain Basics
Brain Structure
| Region | Function | Key Role |
|---|---|---|
| Prefrontal cortex | Executive function | Planning, decision-making, impulse control |
| Amygdala | Threat detection | Fear, emotional memory |
| Hippocampus | Memory formation | Learning, spatial navigation |
| Hypothalamus | Homeostasis | Hunger, thirst, temperature, hormones |
| Cerebellum | Motor coordination | Movement, balance, some cognition |
| Brain stem | Basic functions | Breathing, heart rate, sleep |
Neurotransmitters
Chemical messengers that affect mood and behavior:
| Neurotransmitter | Function | Too Little | Too Much |
|---|---|---|---|
| Dopamine | Reward, motivation | Depression, low motivation | Addiction, mania |
| Serotonin | Mood, sleep | Depression, anxiety | Agitation, restlessness |
| Norepinephrine | Alertness, energy | Fatigue, depression | Anxiety, hypervigilance |
| GABA | Calm, inhibition | Anxiety, seizures | Sedation |
| Glutamate | Excitation, learning | Cognitive issues | Excitotoxicity |
Consciousness
What Is Consciousness?
Consciousness is subjective, first-person experience: the "what it's like" to be you.
Levels of consciousness:
- Conscious awareness - What you're attending to now
- Preconscious - Accessible but not currently attended (your phone number)
- Unconscious - Not accessible to awareness (automatic processes)
States of Consciousness
| State | Characteristics | Brain Activity |
|---|---|---|
| Alert wakefulness | Focused, aware | Beta waves (13-30 Hz) |
| Relaxed wakefulness | Calm, daydreaming | Alpha waves (8-13 Hz) |
| Light sleep | Drifting, easily awakened | Theta waves (4-8 Hz) |
| Deep sleep | Restorative, hard to wake | Delta waves (0.5-4 Hz) |
| REM sleep | Dreaming, paralyzed | Mixed, similar to waking |
| Flow state | Absorbed, effortless | Alpha-theta border |
| Meditation | Focused calm | Alpha, increased gamma |
The Unconscious Mind
Most mental processing is unconscious:
What happens unconsciously:
- Pattern recognition
- Implicit learning
- Emotional reactions
- Motor control
- Language processing
- First impressions
Implication: We often don't know why we do things. Our conscious explanations are often post-hoc rationalizations.
Perception
How We See Reality
Perception is not passive recording. It's active construction.
The process:
- Sensory organs receive stimulation
- Brain processes signals
- Brain constructs interpretation
- We experience the construction (not raw reality)
Key insight: You don't see the world as it is. You see the world as your brain interprets it.
Perceptual Biases
| Bias | Description | Example |
|---|---|---|
| Selective attention | See what we focus on | Missing gorilla in basketball video |
| Confirmation bias | See what we expect | Finding evidence for existing beliefs |
| Change blindness | Miss gradual changes | Not noticing haircut |
| Inattentional blindness | Miss unexpected things | Not seeing person in gorilla suit |
| Perceptual set | Context shapes perception | Same ambiguous shape seen differently |
Top-Down vs. Bottom-Up Processing
Bottom-up: Building perception from sensory data
- Seeing a shape, recognizing it as a face
Top-down: Expectations shaping perception
- Seeing a face because you expect one
Both happen simultaneously. Top-down processing often dominates.
Attention
The Attention System
Attention is a limited resource. You can't attend to everything.
Types of attention:
| Type | Description | Example |
|---|---|---|
| Selective | Focusing on one thing | Listening to one conversation at party |
| Divided | Attending to multiple things | Driving while talking |
| Sustained | Maintaining focus over time | Studying for hours |
| Executive | Controlling attention | Resisting distraction |
Attention Filters
Your brain filters information constantly:
What grabs attention:
- Novelty (unexpected things)
- Threat (dangerous things)
- Relevance (things that matter to goals)
- Salience (bright, loud, moving things)
- Emotion (things with emotional charge)
What passes through:
- Your name
- Threat words
- Things relevant to current goals
- Things you're primed to notice
The Self
What Is the Self?
The self is not a thing. It's a process: a constantly updated narrative.
Components:
- Self-concept: What you believe about yourself
- Self-esteem: How you evaluate yourself
- Self-awareness: Consciousness of your own states
- Self-regulation: Controlling your own behavior
Self-Awareness Levels
| Level | Description | Develops |
|---|---|---|
| Minimal self | Sense of being a body | From birth |
| Objective self | Recognizing self in mirror | ~18 months |
| Autobiographical self | Continuous identity over time | ~3-4 years |
| Reflective self | Thinking about thinking | ~7+ years |
Self-Serving Biases
We're not objective about ourselves:
| Bias | Description |
|---|---|
| Self-serving attribution | Credit success to self, blame failure on others |
| Above-average effect | Rating self above average on most traits |
| Optimism bias | Expecting better outcomes for self than others |
| Blind spot bias | Seeing biases in others but not self |
| Spotlight effect | Thinking others notice you more than they do |
Nature and Nurture
The Interaction
Genes and environment interact constantly:
Genes influence:
- Temperament
- Intelligence range
- Susceptibility to disorders
- Physical characteristics
Environment influences:
- Which genes are expressed
- Skills developed
- Beliefs and values
- Specific behaviors
The truth: It's never just one or the other. Genes create predispositions. Environment shapes expression.
Heritability
Approximate heritability of psychological traits:
| Trait | Heritability |
|---|---|
| Intelligence | ~50-80% |
| Personality | ~40-60% |
| Mental disorders | ~30-80% (varies) |
| Political attitudes | ~40-50% |
| Religiosity | ~30-50% |
What this means: Heritability is not destiny. It's the proportion of variation in a population explained by genes.
Practical Implications
Understanding Yourself
- Your reactions are often automatic, not chosen
- Your perceptions are constructions, not recordings
- Your explanations for your behavior are often wrong
- You're subject to the same biases as everyone
- Self-awareness requires deliberate effort
Understanding Others
- They're running the same basic software
- Their behavior makes sense from their perspective
- They're unaware of their biases too
- Attributing intent is often wrong
- Everyone is constructing their own reality
What You Can Change
- Can change: Behaviors, habits, skills, knowledge, some beliefs
- Hard to change: Temperament, basic personality, fundamental values
- Can manage: Emotions, reactions, biases (with awareness and effort)