Researchers should recognise the full complexity of the human mind

Consumers are influenced by simple marketing messages without being aware of the source of the influence. They are unable to control or counter the effects, said Steven Sweldens, Endowed Professor of Consumer Behavior and Marketing at Rotterdam School of Management, Erasmus University (RSM) delivering his inaugural address Puppets on a String? Studying Conscious and Unconscious Processes in Consumer Research on Friday, 18 May 2018. His research demonstrates that advertisements have automatic effects on consumers’ attitudes towards products and brands. He argued that we should acknowledge that the human mind cannot be neatly divided into two complementary thought processing systems, according to the popular theory that one operates consciously, the other unconsciously. “The reality is much more complex,” he said, “and we as researchers need to embrace this complexity.” 


Prof. Sweldens explained consumer behaviour is an academic subfield of marketing that examines people’s emotions, attitudes, preferences and how they can be influenced. His research in this field has focused mainly on the potential role played by unconscious processes in consumer responses to advertising. “Older theories proposed that humans are at the mercy of subconscious forces, with people only being aware of what’s happening in the conscious mind, but having no idea of what’s in the unconscious mind”.

Sweldens further explained that “more modern psychological theories describe the unconscious mind as a highly sophisticated processing system that can process a lot of information automatically, without our awareness and ability to control it.” Such notions are grounded in a dual system theory of thought, according to which people’s minds consist of a “System 1” and a “System 2.” System 1 is assumed to be based in the primitive parts of the brain, operating unconsciously and uncontrollably, with low effort, and with huge capacity. It is fast, nonverbal, parallel, and associative. System 2 is evolutionarily more recent, resides in the human frontal cortex, operates consciously, controllably, with high effort, has small capacity, is slow, verbal, serial, and based on rules.

The struggle of the dual system theory

Professor Sweldens’ research has tested core propositions of the dual system approach. His research into the way brands become more well-liked through advertising and conditioning procedures is highly relevant to the debate, but so is his research on people’s risk perceptions and self-control performance. The professor has seen support for some of the key predictions of dual process theory, but little support for its strong claim that mental processes should clearly belong to one of two systems with highly separable features.

“The dual process theory was elegant, powerful and grounded by psychology and evolution,” he said. “But explaining too much can be a problem for scientific theories, as scientific theories can never be conclusively proven. It is important they can be held to account by data, have clear potential to be falsified. The dual process theory struggles with this.”

His most important critique is focused on lack of empirical evidence for unconscious associative learning, and alignment problems of the processing properties of the dual Systems. “Researchers argue there is simply no convincing evidence that the features of System 1 or System 2 necessarily co-occur, and a lot of evidence that often they do not. In other words, there is no guarantee that if a process occurs without awareness, that it is also unintentional, uncontrollable, or efficient. In fact, there’s a lot of evidence for processes that are characterized by some of those features but not by others. Our use of language serves as a good example. People are unaware of how they combine sounds into words or which rules they follow to create grammatical sentences in their native language, but using language is still an intentional act, which can be stopped or controlled at any time. The same goes for skills like typing or driving.”

Liking what you see – a passive effect

During his address, Prof. Sweldens talked about the role of evaluative conditioning in advertising, one of the most basic procedures to change people’s liking of products or brands. “Evaluative conditioning effects are very simple on the surface. They simply refer to the fact that if you see a brand or product in combination with something else you like, you’ll like that brand more. Period. This is a very effective advertising strategy, generating robust effects in various settings. Think of Coca-Cola advertising with ice bears or Christmas, think of the use of celebrities endorsing brands, think of the presence of beautiful nature scenes or music you like. All of these increase brand liking. Note that advertising based on these principles says nothing about the product quality, taste or price. It’s just about basic infectious transfers of liking.”

He explained this is a passive effect. “People don’t have to do anything. No behaviour needs to be reinforced. Being exposed to advertising like this will influence your attitude,” Prof. Sweldens said, adding such brand conditioning effects are a key test to the dual process theory. “Evaluative conditioning effects deal with emotions, don’t require language and are associative. That is why they are considered key to test the purported abilities of System 1 – learning without awareness, ability to control etc. Unfortunately, accurately measuring people’s awareness is very difficult, as is investigating whether advertising effects can really be controlled by people. It is exactly in these domains that I believe to have made some important contributions.”

Jingles and unconscious learning

Prof. Sweldens said he believes one danger of believing in dual system theories is that people jump to generalisations too quickly. “For example, in one of our research projects, we showed that advertising based on evaluative conditioning principles can have uncontrollable effects on people’s brand attitudes and consumption decisions. Believers in a System 1 / System 2 dichotomy would then be quick to conclude that such uncontrollable effects must happen unconsciously too. That is problematic, first, because it simply wasn’t demonstrated by the research. And, second, it’s probably not even true. What you’re consciously aware of, might be hardest to control. Think of jingles from ads from your youth that you still can’t get out of your head.”

The professor said he has seen no convincing evidence for a process that would clearly be characterised by all of the System 1 properties. “We should acknowledge the human mind can’t be simply divided in two thought systems.”

He concluded his address by saying that researchers should start recognising the full complexity of the human mind and embrace research that is more detailed, more precise – and less grand – in its claims. “We need to be more detailed and more effortful,” he said.

The full text of the address can be found here


Prior to Prof. Sweldens’ inaugural address, RSM hosted a scientific symposium on campus for international experts. Entitled The operation of conscious and unconscious processes in consumer behaviour, it featured Dr Alex Genevsky (RSM) who presented a view from cognitive affective neuroscience, Prof. Olivier Corneille (Université Catholique de Louvain) from social and cognitive psychology, and Dr Lawrence Williams (University of Colorado) presenting a view from consumer research.

About Steven Sweldens

Steven Sweldens is Endowed Professor of Consumer Behavior and Marketing at RSM, Director of Doctoral Education at the Erasmus Research Institute of Management (ERIM), and Distinguished Research Fellow at INSEAD.

Steven's research interests centre on the psychological laws underlying advertising and the creation of brand attitudes. The importance of this research has been recognised with several awards including the EMAC McKinsey Award for the best European Marketing Dissertation. He was runner-up for the American Marketing Association John A. Howard Award for the worldwide best marketing dissertation, and won several Dutch awards. His work has been published in the top scientific journals in marketing (Journal of Consumer Research, Journal of Marketing Research), psychology (Journal of Experimental Psychology: General, Personality and Social Psychology Review) and OB (Organizational Behavior and Human Decision Processes).

After obtaining his PhD at RSM in 2009, Steven became a marketing professor at INSEAD. There he taught MBA, PhD and executive courses in marketing strategy, social psychological foundations of management, experimental design and marketing in the financial sector. His teaching skills were lauded repeatedly and earned him the INSEAD Dean’s Commendation for Excellence in MBA Teaching. He published a case study on the Renova Paper Company, which quickly became a best-seller and won the highest award at the ECCH Case Awards in 2012 as the fastest-selling new case in business education.

In 2014, Steven returned to RSM where he teaches the marketing core course in RSM’s MBA and EMBA programmes. Since 2018, Steven has served as director of doctoral education and research master programmes at the Erasmus Research Institute of Management (ERIM).


More information

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