ISTP-A vs ISTP-T: what actually differs
Among 2,179 ISTPs in a public Big Five dataset, 34% score on the calm, Assertive-like side of emotional stability and 66% on the stress-sensitive, Turbulent-like side. The two halves differ most on “I get stressed out easily”: 78% of the T side agree, against 21% of the A side.
On the four traits behind the letters ISTP, the halves are nearly the same (at most 4 percentile points apart). ISTP-A and ISTP-T are the same type with a different response to stress.
How ISTP-A and ISTP-T answer
| Statement | ISTP-A side | ISTP-T side |
|---|---|---|
| I get stressed out easily | 21% | 78% |
| I worry about things | 46% | 88% |
| I often feel blue | 16% | 66% |
| I have frequent mood swings | 10% | 65% |
| I get irritated easily | 22% | 77% |
| I am relaxed most of the time | 64% | 21% |
Worry is not only a T trait: 46% of ISTPs on the A side still agree with “I worry about things.” The difference is in how often worry turns into stress, low mood and irritation.
Is ISTP-A or ISTP-T more common?
ISTP-T is more common in this data: 66% of ISTPs are on the T side, compared with 48.2% across all 16 codes. That puts ISTP among the more stress-sensitive codes.
Same type, different stress response
We compared the two halves on Extraversion, Openness, Agreeableness and Conscientiousness. The largest gap was 4 percentile points. So an ISTP-T is not “less ISTP” than an ISTP-A: the four letters fit both equally well. What separates them is one trait, emotional stability, which the four letters do not measure.
Where these numbers come from
16Personalities describes the Assertive (-A) side as self-assured, even-tempered and resistant to stress, and the Turbulent (-T) side as self-conscious and sensitive to stress. Its own -A/-T scores are not public, so we cannot split real 16Personalities results.
Instead we used the trait that description closely resembles: emotional stability, the opposite of neuroticism. We took 19,718 people’s answers to the 50 public-domain IPIP Big Five statements, gave each person a four-letter code the way the 64 Types test does, and split every code at the sample median of emotional stability. In a 64 Types code, the calm half gets the fifth letter C (Composed) and the other half R (Responsive).
Which one are you?
Your four letters do not tell you; only your stress-related answers do. The free 64 Types test measures emotional stability directly and gives it as the fifth letter, with a percentile, so you can see where you fall among ISTPs.
Take the free testHow far to trust these numbers
- Volunteer online sample from about 2012 (61% women, median age 22, 44% in the United States): a description of this sample, not of everyone.
- Our codes come from Big Five scores and match MBTI or 16Personalities letters only partly, so your type there may differ.
- Everyone answered about themselves on one day. A low emotional stability score is a normal trait level, not a diagnosis.
Questions
What is the difference between ISTP-A and ISTP-T?
Only the response to stress. In our data the T side agrees far more often with statements such as “I get stressed out easily” (78% vs 21%), while the four ISTP traits differ by at most 4 percentile points.
Is ISTP-A or ISTP-T more common?
ISTP-T: 66% of 2,179 ISTPs in our analysis, against 48.2% across all codes.
Other types: -A vs -T
Sources
- Open Psychometrics (n.d.). Raw data from online personality tests: Big Five Personality Test, IPIP 50 items (BIG5.zip, 19,719 records, collected c. 2012). Retrieved 22 October 2026, from https://openpsychometrics.org/_rawdata/ (frequencies computed by 64 Types with scripts/type_frequency.py)
- Goldberg, L. R. (1992). The development of markers for the Big-Five factor structure. Psychological Assessment, 4(1), 26–42.
- 16Personalities (NERIS Analytics Limited). Assertive vs. Turbulent personality traits [Identity: Assertive (-A) vs. Turbulent (-T)]. Retrieved 21 October 2026, from https://www.16personalities.com/articles/identity-assertive-vs-turbulent
- McCrae, R. R., & Costa, P. T. (1989). Reinterpreting the Myers-Briggs Type Indicator from the perspective of the five-factor model of personality. Journal of Personality, 57(1), 17–40.