Two More Things That Can Cripple Your Decision-Making: And What To Do About It


You may have read other articles around the internet purporting that a full bladder helps us make better choices. This makes for sensational headlines but isn’t exactly true.
In the previous article to this one I wrote about how feelings of desire can overflow to the decisions we make, so can our self-control. Mirjam Tuk, of the University of Twente in the Netherlands, conducted research into how self-control, or inhibition of desires, might affect us.

In one experiment, participants either drank five cups of water or took small sips of water from five separate cups. Then, after about 40 minutes – the amount of time it takes for water to reach the bladder – the researchers assessed participants’ self-control. Participants were asked to make eight choices; each was between receiving a small, but immediate, reward and a larger, but delayed, reward. For example, they could choose to receive either $16 tomorrow or $30 in 35 days.

The researchers found that the people with full bladders were better at holding out for the larger reward later. Other experiments have found similar results in that the subjects that can show more self control were more adept at making rational choices and controlling their emotions. One study by T. F. Denson, C. N. DeWall andE. J. Finkelcalled Self-Control and Aggression asked participants to use their non-dominant hand for two weeks to do everything. Those that stuck with using their opposite hand (non-dominant) were not only prone to less aggression but could restrain their desires, emotions and feelings allowing them to make better decisions.


Firstly, if you wanted to go to the toilet before reading this article, go now. It’s not actually a full bladder that makes for better decisions but the self-control to hold on. The restraint required to hold your bladder or use your non-dominant hand spills over to your self-control when it comes to making decisions. We’re more likely to choose low-risk options and to avoid impulse decisions when we’re controlling ourselves physically.


You’ve probably heard about how having plants in the office or home is good for productivity and general wellness. It turns out plants and good ventilation are beneficial in more ways than one.

A study of CO2 levels found that as CO2 is increased, even when it’s still below the recommended safe levels, our cognitive ability decrease. The study assessed decision-making in 22 healthy young adults. Their performance on six of nine tests dropped notably when researchers raised indoor carbon dioxide levels to 1,000 parts per million from a baseline of 600 ppm. On seven tests, performance fell substantially more when the room’s CO2 was boosted to 2,500 ppm.

It’s fair to say then, that the higher the CO2 in the room, the more sharply our mental abilities decline. Study co-author William Fisk of Lawrence Berkeley National Laboratory in California concluded that higher CO2 levels were associated with increased student absences and poorer performances on school-type tasks.


NASA scientists have been working to understand this problem and find solutions.  As you might imagine air quality is essential in spacecraft. Their space-age solution was simply to use houseplants to clean the air. Indoor air pollutants including CO2 have been ranked among the top five environmental risks to public health. Stagnant indoor environments allow pollutants to remain at higher levels than we should be breathing in.

Keeping the CO2 levels low in your home or workspace is really important for all cognitive functions, not just decision-making. Having some plants will certainly help, but to keep fresh air circulating try allowing mother-nature to play her part and open a window or two.

Russell BoonComment