LECTURE 1 – H4: Physiological Needs (4,5)
Need: condition within the person that is essential and necessary for growth, well-being, and life.
Need support (food, water, sleep) maintains life and health, nurtures growth, and promotes well-
being, while need thwart (no food/water/sleep) threatens this. Need thwarting is really threating,
therefore the body puts up defences urgent and attention-getting motivational and emotional
states that provide the impetus to act before serious damage occurs.
3 types of needs:
Physiological needs: thirst, hunger, sex
Biological condition that synchronizes brain structures, hormones, and major organs to regulate
bodily well-being and to correct bodily imbalances that are potential threat to growth, well-being
and life.
Psychological needs: autonomy, competence, relatedness
Inherent (inborn) psychological process (exist within human nature) that underlies the proactive
desire to seek out interaction with the environment that can promote personal growth, social
development, and psychological well-being. Everyone needs autonomy, competence etc.
Implicit motives: achievement, affiliation, power
Developmentally acquired (socialized) psychological process to seek out and spend time
interacting with environmental events associated with positive emotions during one’s
socialization history. Arise from our unique personal experiences, thus vary between persons.
People generally not aware of these needs, because they are implicit or unconscious
experiences.
All needs generate energetic and persistent behavior. Difference between needs is therefore through
its effects on direction of behavior. Some needs generate deficiency motivation, whereas others
generate growth motivation.
Deficiency needs: life goes fine, until some state of deprivation (10 hrs since last meal) activates an
emergency-like need to interact with the world in a way that will quiet the deficit (eat food).
Generate tension-packed, urgency-laden emotions (anxiety, frustration, pain, relief)
Growth needs: more subtle. Guide behavior toward a developmental trajectory of growth and well-
being. Generate positive emotions (interest, enjoyment, hope, vitality).
Drive theory: biologically based theory of motivation, physiological deprivations and deficits (lack
water/food/sleep) create biological needs. If need continues unsatisfied, biological deprivation
become potent enough to occupy attention and generate psychological drive.
Drive: the psychological discomfort (felt tension and restlessness) stemming from the underlying
and persistent biological deficit. Drive energize someone into action.
Model of Need-Drive-Behavior Sequence: from satiated state (full/ unmotivated) > deprivation >
bodily need > drive > goal-direction motivated behavior > consummatory behavior > reduced drive >
satiated state.
Physiological Need: a deficient biological condition. Occurs with tissue and bloodstream deficits
(water loss/ physical injury). When intense and unaddressed, need translate into bodily harm.
Psychological drive: not biological. Conscious manifestation of an underlying unconscious need.
Drive has motivational properties. Thus, drive to eat energizes and directs behavior, not low
blood sugar.
Homeostasis: describes the body’s tendency to maintain a stable internal state. Bodily system
mostly steady state of equilibrium (bodily temperature always around 37 degrees). It is actually
the body’s ability to return a system (bloodstream) to its basal state. To do so, people take
action. The reason that they take action is because of motivated drive.
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, Negative feedback: refers to homeostasis’ physiological stop system. Negative feedback stops
behavior. You eat until you are no longer hungry. It signals satiety well before the physiological
need is fully replenished.
Multiple inputs/outputs: drive has multiple inputs or means of activation. Feel thirsty after
sweating, eating salty or donating blood. Also, satiety has multiple outlets, or behavioural
responses. When cold, people can put on jacker, turn up the furnace, or exercise. Thus: drive
arises from different sources (inputs) and motivates different goal-directed behaviors (outputs)
until satiety occurs. Drive intervenes between states op deprivation (input stimuli) and
restorative goal-directed actions (output responses) hand touching hot stove (= antecedent 1)
> pouring cold water over hand (= consequence 1).
Intraorganismic mechanisms: all biological regulatory systems within person that act in concert
to activate, maintain, and terminate the biological needs that underlie drive. 3 main categories:
brain structures, endocrine system (glucose, insulin hormones), bodily organs (liver, stomach).
These bodily mechanisms interact and affect one another in ways that create, maintain and
terminate drive. How internal physiological events cause biological need.
Extraorganismic mechanisms: all environmental influences that play part in activating,
maintaining and terminating psychological drive. Categories: cognitive, environmental, social,
and cultural influences. How cognitive, environmental, social, and cultural events cause biological
need.
Thirst
Loss of water below an optimal homeostatic level that creates the biological need that becomes
psychological thirst. Osmometric thirst (when intracellular fluid [all water inside cells] needs
replenishment) is primary cause of thirst activation. Extracellular replenishment (volumetric thirst)
[water outside cells in blood plasma] helped, but only a little.
Water passing through the mouth provide one thirst stop system (weak one), which is later found to
be the number of swallows during drinking. Also, stomach has thirst inhibitory mechanism (weak
one). Cells themselves must also house negative feedback mechanism. Thus: multiple negative
feedback systems for thirst satiety exist; in the mouth, stomach, bloodstream, and cells.
Most important environmental influence for drinking is taste. Pure water is tasteless and thus offers
no incentive (reward) value above and beyond water replenishment. Sweet tasted water is more
pleasant. Salt, bitter and sour taste water is more unpleasant than tasteless water, thus drinking less.
Drinking occurs for 3 reasons: (1) thirst-related water replenishment, which satisfies biological need,
(2) nonthirsty-related sweet taste; response to attractive incentive value of flavoured water, (3)
nonthirsty-related attraction to, or even addiction to, substance in water (not water itself).
Hunger
More motivationally complex than thirst. Hunger only loosely follows a “depletion-repletion” model.
Hunger regulation involves not only short-term daily processes operating under homeostatic
regulation (depletion and repletion of blood glucose and calories), but also long-term processes
operating under metabolic regulation and stored energy (fat cells). Hunger also affected by cognitive,
social and environmental influences.
Glucostatic hypothesis = homeostatic-based model of short-term appetite. Accounting for onset and
termination of hunger and eating. Blood-sugar levels are critical to hunger; when it drops people feel
hungry and want to eat. Cells require glucose to produce energy. Thus, when cell uses glucose to
carry out its functions, physiological need for glucose arises. Cold temperatures stimulate eating; we
eat more in winter than in summer, because we are cold and need energy to warm up. You have to
stop eating when you are 80% full, because it takes a little extra time for stomach to relay to brain
that it is full. Different foods provide different feeling of satiety, mostly because they differ in amount
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,of protein, sugars, fat, water and size. High protein food (pasta, potatoes, fish) produce greatest
feeling of satiety (feel full), whereas foods that take little time or effort to eat (cake, donut, yogurt,
white bread) produce greatest feeling of lingering hunger (still feel hungry), even if number of
calories in foods is same.
Fat also produces energy (like glucose). Body also monitors its fat cells.
Lipostatic hypothesis: when mass of fat stored drops below its homeostatic balance, fat secretes
hormones into bloodstream to promote hunger. Hormones play critical role in rise and fall of hunger.
Ghrelin = hormone manufactured in stomach, circulated in blood, detected and monitored by the LH.
Ghrelin rise and falls throughout day, peaking around times people normally eat. Eating food causes
rapid fall in ghrelin. Ghrelin is always chronically higher when people are on a diet than when not on
diet. Therefore, dieter feels hungry all the time.
Set-point theory = spin-off theory of lipostatic hypothesis. Says that each individual has a biologically
determined body weight or “fat thermostat” that is set by genetics either at birth or shortly
thereafter. Hunger activation and satiety depend on size (not number) of one’s fat cells, which vary
over time. When fat cells is reduced (by dieting), hunger rises until feeding behavior allows the fat
cells to return to their natural (set-point) size. Thus, hunger is the body’s means of defending its
genetic set point. Set point rises with age.
Environmental influence that affect eating behavior include; time of day, stress, sight/ smell/
appearance/ taste of food. Eating is often a social occasion. Eat more when in presence of others,
especially if they are family/friends. Situational pressure to eat or diet. Also influence whether our
friends are obese.
Sometimes, physiologically regulated body weight does not measure up well to personal or cultural
aspirations. Regulate body weight self > dieting. Dieter attempts to bring eating behavior under
cognitive instead of physiological control (I will eat this much at this time, instead of I will eat when
hungry). However, cognitive controls do not feature a negative feedback system. Therefore, highly
vulnerable to binging. Because (1) we like to think that our cognitive controls and willpower are
stronger than physiological controls and hunger urges; and (2) environmental events (alcohol/
presence others) and our own feelings (depression/anxiety) can easily distract us away from
cognitive control over what we are trying to do. Under conditions of anxiety/stress/alcohol, dieters
become increasingly susceptible to disinhibition (restraint release) of their cognitively regulated
eating style. For dieters: you cannot eat just one. Fating rarely works, because major reduction in
energy etc. Dieters more vulnerable for binge eating. Counterregulation = dieters after consuming a
high-calorie food > they eat very much. Can also be something else as consuming high-calorie food
(e.g. depression/anxiety; anxious dieters eat more, normal anxious people eat less).
Other than surgery, only ways people can prevent or reverse weight gain and obesity are to decrease
eating through self-regulatory strategies (goals, monitoring eating), becoming aware of and
monitoring the environmental influences that affect eating, and increasing physical activity to expend
calories and fat stores. This represents voluntary behaviors rather than physiological processes. So,
not focussing on mastering hunger (through cognitively regulated eating style) and more on goal
setting, self-regulation, mindfulness and exercising.
Figure 4.5:
2 solid horizontal lines connecting hunger to eating represent the glucostatic hypothesis of short-
term appetite in which hunger motivates eating (+) whereas eating satiates hunger (-).
Dashed lines centre: the lipostatic hypothesis of long-term appetite in which eating increases fat
stores, while fat stores stimulate hunger (when too low) and stimulate satiety (when too high).
Physical activity decreases fat stores; environment influences stimulate eating; self-regulatory
motivation (goal setting, monitoring weight) regulated eating.
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, Sex
Sexual motivation and behavior occurs only during female’s ovulation period. During ovulation,
female secretes pheromone, and its scent simulates sexual advances from male. For male, injections
of testosterone can further increase his sexual behavior. Sex conforms to the cyclical physiological
need psychological drive process.
Sexual behavior is influenced, but not determined, by hormones. Sex hormones = androgens
(testosterone), estrogens etc. These hormones rise at times (woman’s ovulation period), and fall as
person ages past young adulthood into adulthood and old age. Androgens mostly contribute to
sexual motivation of males (males have 10x more testosterone), and estrogens mostly to females.
But, in females, andorgens play key role in regulating sexual motivation, with decreases in
testosterone foreshadowing decreased sexual desire.
In men; correlation between physiological arousal and psychological desire is high. Men’s sexual
desire can be predicted and explained in context of their sexual arousal (sexual thoughts,
fantasies) desire, arousal, orgasm, resolution.
In women; correlation between physiological arousal and psychological desire is low. Women’s
sexual desire cannot be predicted and explained by physiological need (estrogen, testosterone)
or arousal (genital engorgement). Women’s sexual desire is responsive to relationship factors,
such as emotional intimacy intimacy needs, being open and receptive to sexual stimuli,
arousal, desire, enhanced intimacy. Not underlying physiological need.
Sexual pleasure is associated with stimulation of subcortical brain’s reward circuitry. In women
oxytocin released not only during sex but also during childbirth and breastfeeding, which creates
warm glow underpinning bonding with one’s offspring. Also, greater feelings of commitment and
calmness/ less stress. For males and females, it facilitates attraction and bonding to partner. Males:
greater commitment to monogamous relationship.
Facial metrics: people’s judgements of attractiveness of facial characteristics. Differs between
cultures, due to socialization, experience, and cultural consensus. Most attractive: neonatal features
(baby; large eyes, small nose), sexual maturity features (status; prominent cheekbones, thick
eyebrow hair), and expressive features (positive emotions; wide smile, higher-set eyebrows,
happiness/openness). Women most attractive: neonatal features. Men: sexual maturity features.
On one hand; facial metric ratings are objective features of faces that yield pan cultural consensus as
to which face are beautiful (faces are beautiful). Other hand; face is beautiful to extent that perceiver
sees youth, status, or happiness-openness (subjective perceptions of youth/status etc. are beautiful).
Sexual script: one’s mental representation of step-by-step sequence of events that occur during
typical sexual episode. Includes specific actors, motives and feelings of those actors, and set of verbal
and nonverbal behaviors that should successfully conclude with sexual behavior. Young male learns
to coordinate his sexual script to coincide with three linear stages in sex response cycle of desire
(excitement), arousal, and orgasm. For females, coordination of sexual script and physical activity is
looser, partly because content of emerging sexual scripts contains little material that is sexual, but
includes events such as falling in love and emotional sharing. With dating sexual scripts transition
themselves from independent, fantasy-based scripts into interpersonal, teamlike script. If couple fails
to coordinate their sexual scripts, their sexual episodes will likely be fraught with distress, conflict
and anxiety, and sexual performance is awkward and unsuccessful.
Sexual schemas: beliefs about sexual self that are derived from past experiences that feature both
positive-approach-oriented thoughts and behaviors (sexual desire/participation) as well as negative-
avoidance-oriented thoughts and behaviors (sexual anxiety, fear, sexual inhibition). These positive/
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