How stress hormones influence judgment, choice and social preferences Tobias Kalenscher Heinrich-Heine University Düsseldorf

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2 How stress hormones influence judgment, choice and social preferences Tobias Kalenscher Heinrich-Heine University Düsseldorf

3 Stress and Decision-Making 3

4 Stress and Decision-Making Stress? 4

5 How do we make decisions? It is not from the benevolence of the butcher, the brewer, or the baker that we expect our dinner, but from their regard to their own interest. The Wealth of Nations (1776) Adam Smith ( ) Our decisions are motivated by self-interest 5

6 How do we make decisions? Rational own-payoff maximizer Sophisticated rational beliefs Stable preferences Maximizes own-payoff Disregards other peoples well-being 6

7 How do we make decisions? Rational own-payoff maximizer Sophisticated rational beliefs Stable preferences Maximizes own-payoff Disregards other peoples well-being 7

8 Sophisticated rational beliefs? A question: You buy a toy for your little son A bat and a ball cost 1.10 The bat costs 1.00 more than the ball How much does the ball cost? 8

9 Sophisticated rational beliefs? Intuitive answer: The ball costs 10 Cents System 1 Intuitive, automatic cognition gut instinct System 2 Slow, analytical and reflective thinking Answer after some deliberation: The ball costs 5 Cents 9

10 Sophisticated rational beliefs? We are not always reflective, sophisticated thinkers Does it get worse under stress? Cognitive Reflection Tasks Stress 10

11 Sophisticated rational beliefs? Stress Cortisol + Noradrenaline Time Only Cortisol 11

12 Sophisticated rational beliefs? We are not always reflective, sophisticated thinkers Does it get worse under stress? Cognitive Reflection Tasks Stress 12

13 Sophisticated rational beliefs? We are not always reflective, sophisticated thinkers Does it get worse under stress? Hydrocortisone Cortisol Cognitive Reflection Tasks Yohimbine Noradrenaline Placebo 13

14 Sophisticated rational beliefs? This means: An increase in cortisol action, but not in noradrenaline, results in......more intuitive, automatic responses...less reflective thinking Margittai et al., PNEC,

15 Sophisticated rational beliefs? We rely more on intuitive judgments at the expense of deliberative reasoning under the influence of the stress hormon Cortisol Margittai et al., PNEC,

16 How do we make decisions? Rational own-payoff maximizer Sophisticated rational beliefs Stable preferences Maximizes own-payoff Disregards other peoples well-being 16

17 How do we make decisions? Rational own-payoff maximizer Sophisticated rational beliefs Stable preferences Maximizes own-payoff Disregards other peoples well-being 17

18 Loss Aversion Would you play this gamble?

19 Loss Aversion Would you play this gamble?

20 Loss Aversion Would you play this gamble?

21 Loss Aversion Would you play this gamble?

22 Loss Aversion Would you play this gamble? Most subjects reject a 50/50 gamble in which the prospective gains are equal to the prospective losses They accept a mixed gamble only when the gains are approximately 2x as high as the losses Losing amount X is more painful than winning amount X is joyful. Subjects are more sensitive to the possibility of losing money than they are to the possibility of gaining the same amount of money. Loss Aversion Tversky & Kahneman, J Risk Uncert,

23 Loss Aversion Cortisol, noradrenaline, loss aversion and risk attitude Hydrocortison Cortisol Yohimbine Noradrenaline Placebo Margittai et al., Neuropsychopharmacology, 2017

24 Loss Aversion Cortisol, noradrenaline, loss aversion and risk attitude 40 choices between receiving amount (x) for sure and a lottery with a.5 probability of either winning amount (y) or losing amount (z). Value function: u w w, or u w w,, = measure of loss aversion loss aversion loss neutral = measure of risk attitude > 1: risk aversion < 1: risk seeking Margittai et al., Neuropsychopharmacology,

25 Loss Aversion Cortisol, noradrenaline, loss aversion and risk attitude Loss Aversion ( ) No Yohimbine Remember: Lambda 3,3 3,1 2,9 2,7 2,5 2,3 Yohimbine *** Smaller = less loss aversion Concurrent action of cortisol and noradrenaline makes subjects less lossaverse 2,1 No Cortisol Cortisol Margittai et al., Neuropsychopharmacology,

26 Loss Aversion Cortisol, noradrenaline, loss aversion and risk attitude Loss Aversion ( ) Risk Attitude ( ) 3,3 No Yohimbine Yohimbine 2,5 2,3 n/s Lambda 3,1 2,9 2,7 *** Mu 2,1 1,9 2,5 2,3 1,7 No Yohimbine Yohimbine 2,1 No Cortisol Cortisol 1,5 No Cortisol Cortisol 26 Margittai et al., Neuropsychopharmacology, 2017

27 Loss Aversion The combined action of Cortisol and Noradrenaline (cf. acute stress) reduces loss aversion, but does not change risk attitude 27 Margittai et al., Neuropsychopharmacology, 2017

28 How do we make decisions? Rational own-payoff maximizer Sophisticated rational beliefs Stable preferences Maximizes own-payoff Disregards other peoples well-being 28

29 How do we make decisions? Rational own-payoff maximizer Sophisticated rational beliefs Stable preferences Maximizes own-payoff Disregards other peoples well-being 29

30 Are We Own-Payoff Maximizing Egoists? Another question You have 15 Your best friend needs some money How much of your 15 would you give him? And how much of 15 would you give to your neighbor if she asked you for financial help? And how much would you give to an unknown stranger on the street? 30

31 Are We Own-Payoff Maximizing Egoists? % money shared Social Discounting: Generosity towards others decreases hyperbolically as a function of social distance between donor and recipient Social Distance Strombach et al., PNAS, 2015; Margittai et al., Hormones Behav,

32 Stress and Social Discounting What is the effect of stress on social discounting? Stress? 32

33 Stress and Social Discounting The tend-and-befriend hypothesis Individuals cope with stress by investing into social relationships during stress Offer costly help to a delimited group of people Expect receiving guard from them in return But: it would be maladaptive and unrealistic to befriend everyone alike Help can only be expected from socially close group of people Hypothesis: Altered social discounting Stress amplifies generosity towards socially close, but not distant others 33

34 Stress and Social Discounting Stressor: Group Trier Social Stress Test 34 Margittai et al., Hormones Behav, 2015

35 Task Stress and Social Discounting Subject (donor) Recipient (here: someone on social distance 50) Social distance is a measure of how close someone feels to someone else Dictator game: You have 15? How much do you want to share with a person on social distance 50? 3x repeated for social distances 1, 2, 3, 5, 10, 20, 50 and 100 Main readout: amount shared at each social distance level Measure of social-distance-dependent generosity Margittai et al., Hormones Behav,

36 Stress and Social Discounting Effects of psycho-social stress on social discounting Stress Group Control Group Margittai et al., Hormones Behav,

37 Stress and Social Discounting Effects of psycho-social stress on social discounting v: value/utility of increasing the well-being of another person on social distance D here: % money shared k: discount parameter determines how steeply generosity decreases across social distance V: height of the discount function can be interpreted as level of generosity towards socially close people Margittai et al., Hormones Behav,

38 Stress and Social Discounting Effects of psycho-social stress on V (generosity towards socially close others) Control Stress Margittai et al., Hormones Behav, 2015

39 Stress and Social Discounting Effects of psycho-social stress on k (steepness of the discount function) Control Stress n/s (p=.08) 39 Margittai et al., Hormones Behav, 2015

40 Stress and Social Discounting After psychosocial stress, people become more generous towards socially close people Friends, family, significant others but not necessarily towards socially distant people Neighbours, teachers, strangers 40 Margittai et al., Hormones Behav, 2015

41 Stress and Social Discounting What is driving the stress-effects on social discounting? 41

42 Psychopharmacology of Social Discounting Hydrocortisone: Cortisol Yohimbine: Noradrenaline Placebo Margittai et al., PNEC, in revision 42

43 Results Psychopharmacology of Social Discounting Placebo Cortisol 60 % Amount Shared Social Distance Margittai et al., PNEC, in revision 43

44 Results Psychopharmacology of Social Discounting Placebo Yohimbine Cortisol Yohimbine + Cortisol % Amount Shared Social Distance Margittai et al., PNEC, in revision 44

45 Psychopharmacology of Social Discounting Effects of pharma administration on V (generosity towards socially close others) 1 0,9 No Yohimbine Yohimbine *** V 0,8 0,7 0,6 No Hydrocortisone Hydrocortisone 45 Margittai et al., PNEC, in revision

46 Psychopharmacology of Social Discounting Effects of pharma administration on V (generosity towards socially close others) Cortisol increases generosity towards close others But yohimbine offsets the increase in generosity caused by cortisol Margittai et al., PNEC, in revision 46

47 Psychopharmacology of Social Discounting Effects of pharma administration on log(k) (steepness of the discount function) -1,5 n.s. -1,7-1,9 log(k) -2,1-2,3-2,5 No Yohimbine Yohimbine -2,7 No Hydrocortisone Hydrocortisone 47 Margittai et al., PNEC, in revision

48 Psychopharmacology of Social Discounting Conclusions 1. Cortisol action boosts generosity......but only towards an inner circle of friends and family...and not towards socially distant individuals 2. The generosity-boosting effects of cortisol are offset by noradrenergic action Cortisol promotes tend-and-befriend, but noradrenaline inhibits those prosocial tendencies % Amount Shared Placebo Cortisol Social Distance 48

49 How do we make decisions? Rational own-payoff maximizer Sophisticated rational beliefs Stable preferences Maximizes own-payoff Censored Disregards other peoples well-being 49

50 Stress, Thinking and Decision-Making Summary 1/2 After enhancing cortisol action, people rely more on intuitive judgments at the expense of deliberative reasoning But the combined action of the stress- neuromodulators cortisol and noradrenaline reduces one of the most prominent decision-biases loss aversion......while leaving risk-attitude unaffected 50

51 Stress, Thinking and Decision-Making Summary 2/2 After psycho-social stress, we become more generous towards socially close others (friends, family...)......but not towards socially-distant recipients (strangers...) Cortisol alone boosts generosity towards socially close others But noradrenergic action offsets the generosity-effects of cortisol 51

52 Stress, Thinking and Decision-Making Take Home Message Stress and stress neuromodulators affect our thinking and decision-making in bi-directional and time-dependent ways Relevance for policy making: knowledge of the neurohormonal stress composition allows better and more accurate predictions of choice and judgment than behavioral observation alone (revealed preferences) Stress 52

53 Acknowledgments Gideon Nave Marian Joels Zsofia Margittai Lars Schwabe Marijn van Wingerden 53

54 The Team Special thanks to the Comparative Psychology team! 54

55 Many thanks for your attention!