Why We Make Decisions Together

Post by Anastasia Sares

What’s the science?

Collective decision-making behaviors have been demonstrated in social animals like bees, ants, and fish. Humans are also social creatures, and like these other species, we often make decisions together, even though we strongly value autonomy. What benefit is there in giving up some of our autonomy and making a decision as a part of a group? This week in Nature Human Behavior, El Zein and colleagues suggested that we decide together in order to dilute risks and negative outcomes.

What do we already know?

Previous research in this area has focused on whether collective decision-making results in a better decision overall. In some circumstances this process is helpful, but other times a group can get derailed and make a non-optimal decision. Since group decisions aren’t necessarily better in terms of accuracy, it is important to understand why we bother with them at all. After all, we like to have a choice when deciding what kind of product to buy, or what career to pursue. Some decisions are made together out of social obligation or a sense of fairness, but this may not account for all of the collective decision-making situations we observe.

What’s new?

The authors propose that one of the main reasons that individuals make decisions collectively is because it minimizes the risk taken by any one member. It’s what animals do when they herd or flock together, making it less likely that any one member is attacked (known as the dilution effect). Humans, even when they are not in physical danger, are very averse to certain emotional risks, especially regret or responsibility for a negative outcome. Making a decision as part of a group reduces the feeling of personal responsibility and can help us to cope with the stress of difficult decisions (like parents deciding whether or not to keep an injured child on life support). It may also protect us from social backlash (like when “whistleblowers” call out bad behavior of very powerful individuals). However, when taking the group perspective and not the individual perspective, the decrease of personal responsibility comes with its own problems: at worst, no one assumes responsibility for negative outcomes, and they are not addressed at all. Think of the bystander effect, where witnesses to an emergency situation are less likely to step in and help if others are present, or the tragedy of the commons, where individuals tend to over-use common resources.


What's the bottom line?

There are a number of factors that push us toward collective decision-making: social inclusion and fairness, the idea that we are smarter together, and, as El Zein and colleagues emphasize, protection from negative consequences. In the future, it will be important to evaluate the relative contribution of these different factors in the drive to collective decision-making. This will help us better understand the behavior of the different social groups and governing bodies that permeate human society. Perhaps then we’ll know when to say, “many hands make light work” and when to say, “too many cooks spoil the broth.”


El Zein et al. Shared responsibility in collective decisions. Nature Human Behavior (2019).Access the original scientific publication here.