Author Archives: karishmarajaratnam

About karishmarajaratnam Twitter- @nudgeism

My New Venture & Blog

It has been a while since I posted on this blog, but that could be explained by the fact that I have been busy setting up my brand new venture, Strattr. Strattr is a digital marketing consultancy that places academic findings from the behavioural sciences at the core of online campaign strategy. We’ve developed a new in-house targeting methodology called Cognitive Targeting, which will use psychological insights to optimise ads for clicks and conversions.

I’m going to be blogging on behavioural science and digital strategy on Strattr’s blog from now on, and I’d love it if you would follow my posts there. You can read my first Cognitive Targeting post on applying insights from embodied cognition research to target according to weather here.

Thank you all very much for reading and I hope to see you on the other side.



How Can Convenience Drive Healthy Behaviour?

school cafeteria

Changing human behaviour can be complex. No mathematical equation can determine how we will act from one situation to the next and this uncertainty presents an obvious challenge for marketers, policy makers and employers alike. Common practice has been to rely on assumptions about how people make decisions, based on what we intuitively know about human thinking. If there is one take away from social psychology though, it’s that your intuition, whether or not you’re a marketer with 15 years’ experience, can be extremely biased. Research in this area goes beyond just telling us that decision makers are irrational beings who’ve crossed the path of no return, by providing insights on the best possible way to learn from these biases, to change human behaviour in the desired direction. The beauty of these suggestions are that they are often simple and can be used by anyone, be it the experienced marketer who wants to optimize ad revenue or a mother who wants to influence her child to eat healthy.

Arguably the most popular and scalable of these principles is that of convenience. “Making it simple” or “making it easy” has proven to have a surprisingly large effect on behaviour. With regards to everyday decision making, if given an easy versus difficult path to choosing, we tend to pick the easier one and this bias determines our subsequent choices. This is not to say that “easy” is the inferior option….choosing the quick and easy path for everyday decisions is adaptive, because it can save us time and effort. However there are a number of hidden implications behind choosing easy and convenient options, and these implications can be used with both good and bad motives.

Consider yourself a customer at a supermarket, waiting in line at the cash counter to pay for your two hour long shopping rampage. You’re pretty hungry for a quick snack. Right next to you is a stand displaying delicious looking chocolate bars. You’re tempted to pick up the chocolate but then a health motive sets in, telling you to snack on fruit instead. But the fruit is all the way at the back of the store, you’re well in line to pay your bill, and the chocolate is right beside you… all you need to do is pick it up and pay for it! What would you (and most others) do?

We’d have to run an actual experiment to make any solid claims, but if a psychologist had to guess, they’d probably say you’d pick the chocolate. That’s because our brains are hard wired to pick convenient (and not to mention hedonistic) options. The power of using convenience to subtly drive behaviour change has been studied most commonly in the domain of health related behaviour. Here’s how this is done with two sets of important people : employees and school students.

The Workplace: If I had to pick the most famous (and probably effective) set of nudges used to change employee behaviour, it would be those conducted by Google’s PiLab. When its North American employees were gaining too many unwanted pounds, the search giant decided it was time to take action against the wretched calories (too many pounds can indeed cause a dip in productivity) by adopting insights from psychologists such as Cornell Food Lab’s Brian Wansink. Here are two of their interventions, which involved capitalizing on convenience:

1)  Making M&M consumption more laborious: By moving M&M’s from gravity bin dispensers to opaque jars, the PiLab ensured that eating M&M’s was not as convenient anymore….employees now had to go searching for them.

The result?

“We found that when we moved the M&Ms from those gravity bins to these containers — didn’t take them away, everything’s still there — in seven weeks, New York Googlers consumed 3.1 million fewer calories from M&Ms,” Jennifer Kurkosi, Google PiLab for abc news 

2)  Water vs. Soda: Moving water bottles in the coolers to eye level and sodas to the bottom shelf meant more employees chose a bottle of water over soda, when thirsty. It’s simple, really: water is now the more convenient option, while soda is the more effortful one.

The Lunchroom: Convenience has also been used to encourage healthier consumption in school cafeterias. A study by Wansink and colleagues found that increasing the convenience of eating fruit can increase the consumption of fruit! Slicing apples up using a fruit slicer increased apple sales by 71 percent in middle schools. These results were tempting for Forest Hill High School, which begun selling sliced fruit in plastic bags to their students. It was found that thenumber of students who selected fruit had increased by 18.4 percent, two weeks later.

Another health nudge experiment capitalizing on the principle of convenience was conducted by Denmark’s INudgeYou team. Their field experiment found that simply re-arranging a buffet can significantly impact the kind of food that is consumed. Read more here.

We live in a world where we are consistently bombarded by stimuli and choices. Limited time (yes, school goers have lives too) makes us prefer choosing options that reduce our cognitive load, options that are convenient. Our brains favour convenience more than we realise, and understanding this insight can give marketers, employers and school authorities advantage when designing health related behaviour change interventions.


Photo source :

Loneliness may be deadlier than you think.


On the tragic evening of 23rd May 2014, Southern California’s Isla Vista witnessed a vicious killing spree, leaving 6 innocent victims dead and many injured. The California police have identified the perpetrator to be 22 year old Elliot Rodger, a student at the University of California at Santa Barbara. Rodger allegedly shot himself after committing the crimes.

Just minutes before embarking on his rampage, Rodger emailed his parents a 137 page account of his own perceptions of his life, and the triggers that led up to the incident. Even a brief run through of the document will make evident that Rodger’s life was plagued with loneliness and isolation. While one cannot loosely claim that loneliness solely caused the killings (loneliness more likely interacted with other causal emotional states), what’s clear is that it was key amongst the various negative emotional states Rodger experienced.

Loneliness is also a recurring theme in Rodger’s “retribution videos”, which he published in the weeks that preceded the killings. In the videos, he talks about experiencing a life of loneliness and rejection ever since he hit puberty. This perceived isolation is mainly spoken about in the context of romantic relationships and his inability to find a girlfriend, unlike many of his peers. He blamed young girls for not paying attention to him and expressed anger towards young boys, whom he felt were undeserving of their beautiful girlfriends.

Here are a couple of excerpts from the videos, all of which mention a state of isolation:

“Hey, Elliot Rodger here. It’s truly a beautiful day, but as I’ve always said, a beautiful environment is the darkest hell, if you have to experience it alone. And sadly, I have been alone for a very long time.”

“For the last eight years of my life, ever since I hit puberty I’ve been forced to endure an existence of loneliness, rejection and unfulfilled desires all because girls have never been attracted to me.”

“I’ve had to rot in loneliness. It’s not fair.”         

The destructive power of loneliness has been studied in depth by neuroscientist John Cacioppo at the University of Chicago. Cacioppo argues that human beings are a social species that thrive on social connectedness, and the deprivation of such connectedness can have a number of adverse consequences in our lives. This deprivation needn’t be objective; it can also be perceived, as in the case of a college student like Rodger feeling isolated and lonely even when physically surrounded by his family and fellow UCSB students.

Research has found that loneliness can lead to a number of negative outcomes, including faster cognitive decline, depression and negativity. Cacioppo’s research suggests that the lonely view themselves to be passive victims of their social world and often feel unsafe, therefore heightening their own sensitivity towards threat. He believes that this increased attention to threat caused by loneliness can affect a lonely person even outside of their conscious awareness. For instance, lonely individuals are often conscious of a desire to connect/reconnect with people, but while attempting to do so, their social interactions are often plagued with attentional and memory biases that confirm their belief that they are in a threatening situation. Basically, if you’re subconsciously looking for danger, chances are that you’re more likely to see it. Press reports indicate that Rodger had made several attempts to connect with women in his early teens, almost all of which ended in drunken brawls and humiliating arguments; behaviour that is seemingly consistent with this theory.

Cacioppo’s research additionally suggests that not only is loneliness sad, but it can also be dangerous. It was found that when viewing negative social images (i.e. disturbing images of people) in an fMRI scanner, the brains of lonely people showed lesser activity in the temporal parietal region, which is responsible for empathy, suggesting that loneliness may adversely affect empathy.

Loneliness has also been linked with physical pain. A study conducted by Eisenberger and colleagues in 2003 suggests that the brain bases of loneliness and physical pain are the same. In this study, participants played a virtual ball toss game whilst in the fMRI scanner. Participants believed they were playing with two other anonymous players online. What each participant didn’t know is that they were actually playing a computer program, which was pre-set to ensure that the participant is included by the players only for the first two minutes of the game, and rejected in the remaining time. This social isolation and rejection showed increased activity in the dorsal anterior cingulate cortex, an area associated with physical pain.

Social isolation can also make people feel cold…..quite literally.  In one study at The University of Toronto, researchers Chen-Bo Zhong and Geoffrey Leonardelli first asked some subjects to remember times when they were socially excluded such as being left out of a group lunch meeting and others to remember times when they were socially included, such as being invited to one. Next, in a seemingly unrelated task, all the subjects were asked to estimate the temperature of the room. It was found that people remembering social exclusion rated the room to be chillier than people who remembered social inclusion. Their second study found that subjects who were socially isolated preferred warm food over cold, as measured by their ratings in a subsequent task.

“Loneliness is stigmatized….the psychological equivalent of a person being a loser in life or a weak person” John Cacioppo, at TEDxDesMoines, Sept.2013

The fact that isolation can affect our mental and physical state to such a large extent makes it an important area for further investigation on the clinical triggers that lead to violence. However, loneliness isn’t something human beings necessarily want to associate themselves with, which can make this emotional state difficult to measure in the laboratory; a lonely person often suppresses such emotions, causing them to withdraw from society even further. While Rodger openly spoke about his lonely state in his retribution videos, his written account suggests that his loneliness was suppressed in his early adulthood and was something he was greatly ashamed of at the time.

Additionally, loneliness is often trivialized in society. It is rare to see loneliness being addressed as an issue that is as dangerous as substance abuse or even obesity. Nevertheless, the empirical evidence on the negative consequences of loneliness suggests that it may be deadly to ignore its existence. The Elliot Rodger case is evidence of how the failure to adequately address and deal with a lonely mental state can contribute towards the development of violence, hate, and a desire to harm within a young boy who may have acted differently, had he not felt isolated.


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!

Behavioural Design: What Urban Planners Can Learn From Sweden.

My article contribution to behavioural design blog “Selouk”. Hope you enjoy it!


by Karishma Rajaratnam

Sweden’s success in reducing its road related deaths has been a hot topic in recent months, with both the Economist blog and Fast Company featuring its successful road design. According to The Economist “Sweden’s roads have become the world’s safest”, with road deaths last year hitting a record low. Overall, the number of deaths due to road accidents in Sweden has fallen by four fifths since 1970. Despite their attempts, other developed countries such as America and those across the EU have not been as successful as Sweden in reducing road related deaths.

Sweden’s developed roads and pedestrian crossings are clearly a result of the skill and technique of its designers and urban planners, in coalition with technological advances that make progressive design possible. However, if skilled labour and technology are the sole contributing factors in reducing transport related deaths, why then, do many developed countries (which…

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Adaptively Rational.

In an economically rational world, individuals will maximize personal advantage by carefully weighing the costs and benefits of each of their decisions. Yet research in Behavioural Economics (BE) and Social Cognition has shown that people often make decisions that violate the axioms and models of standard economic theory- we choose immediate, smaller rewards over waiting for larger ones, we engage in behaviour that is damaging to health such as smoking and binge drinking and in general, we behave in ways that are seemingly against our own self interests. This evidence has led to the belief that human beings are irrational decision makers – and this irrationality can have economic, personal and social costs.

Irrationality, bias, fallacy- these have clear negative connotations. Often found to be the reason why we don’t take our medication, drink and drive, shop excessively and buy unhealthy food items in the supermarket, they form a part of our cognition that many wouldn’t particularly brag about. However despite being victims of these woeful biases and blunders, human beings have evolved to adapt, survive and reproduce. Our survival is dependent on the decisions we make and from an evolutionary perspective, some of our seeimingly irrational biases are actually rooted in rationality, for they have enabled the human species to survive in a world that can be fierce, competitive and dangerous. For example, let’s consider one of the most commonly cited concepts in behavioural economics – loss aversion, which is the tendency of individuals to prefer avoiding losses to acquiring gains of equal magnitude (e.g. Kahneman, 2011). While loss aversion has been demonstrated to be a contributing source to many of our sub-optimal decisions in the modern world, loss aversion effects have recently been found to be domain specific, with loss aversion being adaptive in the context of self protection. When our environment is threatening or fearful, being loss averse makes more adaptive sense than being gain focused (Li, Kenrick & colleagues, 2012).  Similarly, the in group  bias- the tendency to favour ones ‘in group’ has its evolutionary advantages- favouring your partner’s wellbeing over others’ leads to reproductive success (Haselton et al., 2009). ‘Motivated reasoning’ – our tendency to engage in selective recall that suits our current situation, can be highly adaptive in the domain of performance and persistence (Nettle, 2004). When studying for a final exam, recalling the previous times you were rewarded for studying hard is more likely to motivate you work hard again, compared to thinking about the times you tried and failed.

Fast and frugal heuristics-

Linda is 31 years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in anti-nuclear demonstrations.

Which is more probable?

  1. Linda is a bank teller.
  2. Linda is a bank teller and is active in the feminist movement.

90% of those asked this question in a famous study by Kahneman and Tversky, chose option 2. This answer violates the logic of probability, because when you specify a possible event in greater detail (such as in example 2), you lower its probability (Kahneman, 2011). Yet people tend to choose option two because it seems more ‘representative’ of Linda. Here, people are using a heuristic. Heuristics are simple rules of thumb that are typically used when individuals have limited information or cognitive ability to engage in complex decision making. They have been found to be the cause of many of our sub-optimal decisions.

Heuristics are an important topic of study in the area of Bounded Rationality, which proposes that human decisions are limited by cognitive and time constraints. A group of researchers (e.g. Gigerenzer, Reimer & Reiskamp etc.) argue that as we cannot possibly know everything about the world we live in, our decision making environment favours bounded rationality. Therefore in this case, cognitive shortcuts can help us make more accurate decisions. Gigerenzer (2000) claims that heuristics are fast and frugal- they are simple and require little information, and this is often sufficient to make good decisions in an uncertain environment. For example, when information is limited, individuals sometimes rely on memory to make inferences about a criterion. In this case they use what is known as a ‘recognition heuristic’. Gigerenzer and colleagues posit that this heuristic is simple, economical and adaptive. A famous study by Goldstein & Gigerenzer (2002) in support of this claim showed that when American and German students were asked which city had a greater population- San Antonio or San Diego, German students were more likely to answer correctly-San Diego. This was because German students were likely to be more familiar with San Diego (compared to American students, who were equally familiar with both) and could use the recognition heuristic in this case.  Here, ignorance seems to be bliss indeed, as the heuristic aids information search for the German students accurately…as they are more familiar with San Diego, they choose it (the heuristic is also famously known as the less is more heuristic).

This research throws light on the importance of Ecological Rationality, which emphasizes understanding the context in which decisions are made before labelling behaviour as irrational. This has important implications for designing behaviour change interventions, with the key lesson being that biases that appear irrational in one context can be perfectly rational in another. On that note, here’s to looking back at all our years preceding 2014 with rosy retrospection 🙂


Goldstein & Gigerenzer (2002) Models of Ecological Rationality : The recognition heuristic. Psychological Review,109.

Haselton et al (2009) Adaptive rationality- an evolutionary perspective on cognitive bias. Social Cognition, 274.

Li, Kenrick, Griskevicius & Neuberg (2012) Economic Decision Biases and Fundamental Motivations: How Mating and Self-Protection Alter Loss Aversion

Kahneman (2011) Thinking, fast and slow.

Rewards, Incentives and Tennis Tournaments.

Rafael Nadal’s loss in the first men’s round of Wimbeldon 2013 was a shock to tennis enthusiasts around the globe, many of whom were disappointed and outraged at the star player’s premature defeat. Even if Nadal’s rugged Spanish looks had a role to play in inspiring these emotions (C’mon ladies, who are you fooling?), jokes apart, most people would regard him as an ‘expert’, ‘a top-ranked player’ and most importantly, a ‘favourite’. Yet, Nadal lost the match to Lukas Rosol, a 135-th rank player (Nadal is currently ranked world No.1). What sparked even more outrage was Roger Federer’s loss in the second round to Sergiy Stakhovsky, who was later labelled ‘The Roger Federer Slayer’ (The Independent, June 2013). A seven time Wimbledon champion, Federer was expected to get much further in the game, if not win the trophy itself. If asked to guess what affected the star’s performances, perhaps one would suggest that they were not in their best form during those matches, or maybe even that their opponent’s game improved.

Another explanation could be that the players experienced what is known as ‘choking under pressure’. Many individuals have faced instances of seemingly insurmountable obstacles in their lives, leading to stress and pressure. The final you have been preparing for and the penalty shootout which will win your team the cup, both have one thing in common- they each have a considerable reward at stake. For the student it means a stronger application to graduate school, for the soccer player it means a cup, money and approval from his/her team. It is in these instances of high stress that choking under pressure is highly prevalent, affecting performance negatively. There are a number of explanations for this phenomenon, one being the distraction theory (Baddeley, 2003) which posits that the worry and stress that accompanies pressure causes distraction, eventually leading to poor performance. The explicit monitoring theory, on the other hand, posits that in the face of pressure, individuals may direct step by step attention to the task, which disrupts their natural attention focus. This exercise of attention is dysfunctional, causing poor performance (Baumeister, 1984; Beilock & Carr, 2001).

While these theories are well cited in the literature, an interesting take on choking under pressure was proposed by researchers at Utrecht University – Erik Bijleveld, Ruud Custers & Henk Aarts (2011). They posit that subtle cues in the environment which indicate that a valuable incentive is at stake can lead to choking under pressure. This is based on the finding that on-going mental processes are disrupted when reward cues enter conscious awareness (Bijleveld, Custers & Aarts, 2011; Zedelius, Veling, & Aarts, 2011). This research was specifically conducted to suit the context of tennis tournaments as in some finals; trophies are prominently displayed near the court, within clear vicinity of the players. The presence of the trophy makes it a high incentive situation, thereby increasing the probability of the occurrence of choking under pressure. Their hypothesis was based on archived data of tennis finals between 2007-2009. Interestingly, they found that choking under pressure occurs for ‘favourites’ – players with high world rankings – rather than underdogs.  This hypothesis was made based on previous literature, which shows that individuals who have enjoyed previous successes are more vulnerable to choking (Bijleveld, Custers,& Aarts, 2011; Zedelius, Veling, & Aarts, 2011). For example, research (Jordet, 2009) shows that soccer players are more likely to miss penalties after they gain ‘super star-status’.

Therefore, they found that in the case of tennis finals, favourites tend to choke under pressure when a subtle reward cue, associated with the large incentive at stake (the monetary incentive), is present in the finals environment. The study suggests that trophies kept by the court, within the favourite’s vicinity, trigger distracting thoughts which affect performance negatively, thereby leading to choking under pressure. However it is important to note that the reward cue doesn’t directly affect match outcomes- while it may lead to a more exciting match, it doesn’t necessarily predict the outcome directly. It would more likely result in a favourite not playing as well as ‘he/she always does’.

The study indicates that the simple presence of a subtle reward cue can nudge star tennis players’ performances in a particular direction. The findings from this study give us an in-depth understanding of the motivating (and de-motivating) power of incentives. A high stake incentive may be motivating to some, but may backfire for others, based on the situation. The effect that incentives have on us can be unconscious and when an incentive is large, it may affect our performance in unexpected ways. The Utrecht University study on choking suggests a possibility that may have previously been questioned by skeptics- factors in the external environment can significantly influence a players (‘favourites’ in this case) performance in the game.

To think that the invincible looking people in the images below can be victims of the human mind too.




Baddeley, A. (2003). Working memory: Looking back and looking forward.Nature Reviews Neuroscience, 4, 829–839.

Baumeister, R.F. (1984). Choking under pressure: Self-consciousness and paradoxical effects of incentives on skillful performance. Journal of Personality and Social Psychology.46, 610–620.

Beilock, S. (2010). Choke: What the secrets of the brain reveal about getting it right when you have to. New York, NY: Simon and Schuster.

Bijleveld, E.,Custers, R. & Aarts,H.  (2011) When favourites fail: Tournament trophies as reward cues in tennis finals, Journal of Sports Sciences, 29:13, 1463-1470

Zedelius, C.M., Veling, H., & Aarts, H. (2011). Boosting or choking – How conscious and unconscious reward processing modulate the active maintenance of goal-relevant information. Consciousness and Cognition 20, 355–362.