Tag Archives: social proof

A Healthy Nudge.

HealthifyMe, an online fitness planner and calorie counter which helps people adhere to a health and weight loss regime, often sends its users email reminders to follow up on their health plan. I couldn’t help but notice that some of these reminders have behavioural nudges hidden in them. Here’s a peek at one of the emails, followed by my interpretation of the influence attempt:


1) Social Norms: “623 people tracked 4951 meals on HealthifyMe yesterday! We noticed you weren’t one of them”.

Using descriptive social norms to change behaviour is a commonly used behaviour change strategy. Telling people what others are doing influences them to conform to the norm or “join the herd”. According to this theory, an influence tactic which points out that many people in one’s community engage in undesirable behaviour can be particularly destructive (e.g. telling teenagers how many other teenagers in their school smoke is likely to increase smoking). On the other hand, pointing out a community’s desirable behaviour can be surprisingly effective.

By claiming that 623 people tracked meals on the website yesterday, and stressing that I clearly wasn’t one of them, HealthifyMe is not only activating feelings of guilt at failing to keep my healthy lifestyle commitment, it is also telling me that I’m not doing what the other members are doing: consciously working on my nutrition plan. I’m now in the “out-group”.

2)  Similarity: “Check out healthy choices that were logged on HealthifyMe yesterday by people just like you: Roti, Apple, Green tea without milk (sugar free), Lentil Dhal and boiled egg white.”

Human beings have a tendency to favour things (and people) that are similar to themselves. By telling members that people “just like them” have been searching for specific types of food/drink items, HealthifyMe is tapping into the similarity bias.  There’s a pattern here: while the social norms message above relates to a broad population of individuals who tracked meals on the website, the similarity message narrows it down to a specific sample of people who are “similar” to the user based on individual demographics and HealthifyMe search behaviour.

There’s another Nudge in there….leave a comment if you can spot it!