| Abbreviation | Definition |
|---|---|
| IPEP | Institute for Psychology of Elite Performance |
| IPPA | International Positive Psychology Association |
| IPPQ | iOpener People and Performance Questionnaire |
| IPTS | Interpersonal Psychological Theory of Suicide |
| IPW | Intelligence for Psychological Warfare |
| IPWB | Index of Psychological Well Being |
| IRM | Innate Releasing Mechanism |
| IRSP | International Review of Social Psychology |
| ISAP | International Symposium on Aviation Psychology |
| ISC | Indirect Self-Control |
| ISCP | International School of Canine Psychology |
| ISCP | International Society for Comparative Psychology |
| ISIP | Idaho Society of Individual Psychology |
| ISP | Integral Somatic Psychology |
| ISPA | International School Psychology Association |
| ISPG | International Society of Psychiatric Genetics |
| ISPP | International Society of Political Psychology |
| ISSP | International Society Of Sport Psychology |
| ISTP | Introversion, Sensing, Thinking, and Perceiving |
| ITAP | Imagination on TAP |