First Study Published Confirming Key Propositions of TMT

Two Minds Theory suggests that Intuitive-level variables have a strong effect on people’s everyday experiences and behaviors (and in fact, that only the Intuitive system is involved in producing behavior). Because the Intuitive system operates outside of conscious awareness, TMT also suggests that people aren’t aware of all the things that affect their immediate experiences and behaviors.

We tested these key propositions in a study just published in the January/February issue of the Journal of the Association of Nurses in AIDS Care, in which we used daily surveys and ambulatory sensor measures (Fitbit Alta HR devices) to predict everyday ups and downs in the experience of fatigue among people living with HIV. Fatigue is one of the most common symptoms reported by people with HIV, and it can seriously impair people’s ability to accomplish everyday tasks. We asked people to complete a validated short survey on fatigue every day on their smartphones, at random times. The surveys confirmed that people had more fatigue than would usually be seen in healthy adults, even though their HIV was under control with effective treatment. Most people’s fatigue also went up and down quite a bit over the 30 days for which we monitored them.

In relation to TMT’s first prediction, that everyday experiences come out of the Intuitive system, we found that daily fatigue was significantly related to physical activity, to sleep, and to stress. The stress relationship was seen on daily surveys, which are close to everyday experience but might still be measuring the Narrative rather than the Intuitive system. But we were particularly excited to also see a relationship between subjective fatigue and stress when we measured stress with a physiological metric called heart rate variability (HRV). Low HRV suggests an unhealthy stress response, usually because people have trouble recovering from stressful situations: Their heart rate stays elevated (so it shows less change, or variability) long after the initial stressor is gone. On the daily surveys, fatigue was particularly related to avoidant coping (not dealing with a stressor head-on), and with other chronic stressors like lack of control over one’s life, lack of social support, and the experience of stigma due to HIV. These findings mirror a previous study in which we used daily surveys to predict HIV medication adherence, and found in that case that the day-by-day measures were in some cases better predictors than a Narrative-level assessment like “on average, how has your mood been over the past 30 days?”

TMT’s second major prediction is that many of the factors that affect behavior are outside of consciousness. We confirmed this prediction using sensor data, which captured information on activity, sleep, and heart rate without needing to ask our participants directly. All of those non-conscious factors did in fact predict fatigue. But even more importantly, data from qualitative interviews showed that our participants themselves were not aware of these factors or their potential connections to fatigue. Our participants often said they were surprised when they saw their own Fitbit data, because they didn’t know how little they moved or how poorly they slept. The fact that these factors did predict fatigue, without our participants being aware of their own self-care behaviors, is a strong confirmation of TMT’s assertion that many variables affecting our everyday experiences are outside of consciousness.

You can read the full study here, or listen to a podcast in which I talk about the results. Thank you to my collaborator Dr. Mary Beth Makic who was PI on the study, and to our great research team.