Chemical messengers
Comprehensive study guide for IB Psychology
Study Notes
Mark Scheme
SECTION A MARK SCHEME (4 marks) Must Include: • Endocrine system and bloodstream transport • Slower/longer-lasting than neurotransmitters • Specific hormone (e.g. oxytocin, cortisol) • Origin gland (e.g. hypothalamus, pituitary) • Hormone level linked to social behaviour • Biobehavioral synchrony OR parental bonding example
Link Formula: "Increased [hormone] levels facilitate [behaviour], showing how the endocrine system regulates [psychological process]."
Watch Out: Don't say hormones work "in the brain"—they travel via bloodstream. Don't confuse hormone speed with permanence; longer-lasting doesn't mean faster.
SECTION B MARK SCHEME (6 marks) 0 marks: No relevant knowledge. 1–2 marks: Basic definition of hormones; minimal application; limited terminology. 3–4 marks: Accurate description of hormone mechanism; some application to scenario; partial link. 5–6 marks: Clear distinction between hormones and neurotransmitters (distance, speed, duration); specific hormone named with origin gland; explicit link to scenario behaviour (e.g., cortisol → impaired working memory → performance drop); sophisticated terminology (e.g., "biobehavioral synchrony", "glucocorticoid receptors").
Why Full Marks
Hormones correctly distinguished from neurotransmitters by distance, speed, and duration; oxytocin production (hypothalamus) and release (pituitary) accurately identified; "biobehavioral synchrony" demonstrates sophisticated terminology; parental bonding example explicitly linked to the biological claim.
Detailed feedback: • Clear distinction between hormones and neurotransmitters (distance, speed, duration) — excellent • Accurate identification of oxytocin's production (hypothalamus) and release (pituitary gland) • Example of parental bonding is well-developed and explicitly linked • "Biobehavioral synchrony" is sophisticated, appropriate terminology • Non-definitive language used well ("associated with," "correlates with") Minor note: The phrase "biological trigger" is slightly informal — "biological mediator" or "neuromodulator" would be more precise. No mark deduction.
Model Answer
Section A Sample Answer
Hormones are chemical messengers secreted by glands in the endocrine system directly into the bloodstream. Unlike neurotransmitters, which signal across synapses, hormones act over longer distances and produce slower, more long-lasting effects. One such hormone is oxytocin, produced in the hypothalamus and released by the pituitary gland. It acts as a biological trigger or mediator for complex social behaviors, including trust, empathy, and bonding.
A specific example of this is the role of oxytocin in parental bonding. Research has found that when parents interact with their infants, measuring salivary oxytocin levels reveals a significant increase that correlates with affectionate touch and biobehavioral synchrony. High levels of this hormone are associated with increased caregiving behaviors and emotional attachment. This demonstrates how oxytocin influences parental bonding behavior, supporting the biological approach's claim that hormones regulate complex social interactions.
Section B Sample Answer
Chemical messengers are substances—including hormones, neurotransmitters, and pheromones—that transmit signals between cells to regulate physiological and behavioral responses. In this scenario, the high-tech environment acts as a stressor for some students, triggering the adrenal glands to release cortisol into the bloodstream. Elevated cortisol binds to glucocorticoid receptors in the prefrontal cortex, which is associated with the suppression of synaptic activity and impaired working memory. This explicitly demonstrates how chemical messengers influence behavior, as the physiological release of cortisol provides a biological mechanism for why students who feel "out of place" experience a performance decrease.