1 Introduction
1.1 The Costs and Benefits of Gratitude Expression
1.2 Physiological Responses to Challenge and Threat
1.3 Individual Differences and Gratitude Interventions
1.4 The Present Study
2 Method
2.1 Participants
2.2 Study Design
Questionnaires | Continuous recording of physiological parameters × 2 (grateful and neutral) | Questionnaires | Follow up | |||||
---|---|---|---|---|---|---|---|---|
Depressive symptoms and trait gratitude | Baseline (3 min) | Challenge/threat evaluations | Grateful/neutral SMS preparation (3 min) | SMS sending (grateful/neutral) | Recovery (3 min) | Invitation to continue the intervention in daily life | Motivation and behavioral intentions towards the intervention | Intervention completion rate (after three weeks) |
2.3 Measures
2.3.1 Challenge/Threat Cardiovascular Markers
2.3.2 Challenge and Threat Evaluations
2.3.3 Depression Symptoms
2.3.4 Gratitude Trait
2.3.5 Motivation
2.3.6 Utility Beliefs
2.3.7 Social Norm Beliefs
2.3.8 Self-control Beliefs
2.3.9 Behavioral Intention
2.4 Gratitude Expression via Texting
After three minutes of preparation, participants received further instruction:Think of a person to whom you are grateful for something. If possible, it should be a person to whom you rarely express gratitude or have never thanked him or her before. Consider what you would like to write to this person. May this be something personally important to you, or perhaps something that you have not thanked yet for, or you feel that you have not thanked enough. Soon you will be asked to send this person a text message expressing your gratitude for this very thing. Let your SMS consists of at least 10–15 words. You will have three minutes to think about its content.
Turn off airplane mode on your phone. Write and send an SMS to the person of your choice containing an expression of gratitude. After sending the SMS, switch your phone back to airplane mode.
Soon you will be asked to send to a person of your choice a text message with a neutral (e.g., informative) content. You will have three minutes to think about its content.Turn off airplane mode on your phone. Write and send an SMS to the person of your choice containing what you have prepared. After sending the SMS, switch your phone back to airplane mode.
2.5 Daily Gratitude Intervention
In recent years, psychologists have established that there are exercises that can increase well-being and happiness. One of them is the “Letter of Gratitude.” This exercise consists of writing a letter or a message of gratitude to someone. The note is sent to the addressee via text message, e-mail, or traditional mail. The exercise involves writing three letters of gratitude, each at an interval of one week.
2.6 Physiological Reactivity
2.7 Analytical Strategy
2.7.1 Preliminary Analysis
2.7.2 Main Analysis
3 Results
3.1 Preliminary Analysis
Parameter | Neutral condition | Gratitude condition | ||
---|---|---|---|---|
M | SD | M | SD | |
TPR baseline | 1.03 | 0.36 | 1.04 | 0.37 |
TPR task | 1.05 | 0.36 | 1.06 | 0.36 |
CO baseline | 5.57 | 1.21 | 5.55 | 1.22 |
CO task | 5.68 | 1.20 | 5.69 | 1.23 |
HR baseline | 79.1 | 10 | 77.8 | 10 |
HR task | 80.23 | 10 | 79.9 | 10 |
Challenge evaluation | 33.00 | 7.00 | 35.00 | 7.00 |
Threat evaluation | 25.00 | 11.00 | 28.00 | 11.00 |
3.2 Main Analysis
1. | 2. | 3. | 4. | 5. | 6. | 7. | 8. | 9. | 10. | 11. | |
---|---|---|---|---|---|---|---|---|---|---|---|
1. Behavior | – | ||||||||||
2. Intention | .23** | – | |||||||||
3. Utility beliefs | .16* | .63*** | – | ||||||||
4. Social norm beliefs | .09 | .43*** | .61*** | – | |||||||
5. Self-control beliefs | .12 | .47*** | .41*** | .20** | – | ||||||
6. ∆Challenge evaluation | .01 | .15* | .18* | .17* | .11 | – | |||||
7. ∆Threat evaluation | − .03 | − .08 | − .09 | .01 | − .08 | − .16* | – | ||||
8. ∆Total peripheral resistance | .01 | − .14 | − .21** | − .14 | − .12 | − .05 | .06 | – | |||
9. ∆Cardiac output | .01 | .12 | .18* | .19* | .18* | .05 | .07 | − .54** | – | ||
10. Depressive symptoms | .03 | − .11 | − .16* | − .17* | − .22** | − .04 | .12 | .11 | − .20** | – | |
11. Gratitude | .06 | .32*** | .49*** | .34*** | .24*** | .16* | − .06 | − .02* | .20** | − .30*** | – |
12. Sex | − .10 | − .10 | − .09 | − .04 | − .02 | − .08 | .03 | .16 | − .12 | − .05 | − .22** |
M | 11.10 | 16.30 | 15.90 | 12.00 | 1.30 | 3.19 | − 0.01 | 0.03 | 16.8 | 30.90 | |
SD | 4.30 | 3.59 | 3.27 | 4.55 | 5.73 | 8.80 | 0.14 | 0.51 | 10.30 | 5.70 |