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Can´t think of a title because I have worked on this blog for too long

When I sign up for SONA experiments, I instantly start looking for studies with describtions that promise some interaction or at least some kind of thinking but please, PLEASE not another hour of constantly clicking the same two keys on my own in a small, boring research room.

Everyone has probably experienced what researchers call participant fatigue at some point. The study lasts so long and becomes so repetetive that it gets more and more difficult to stay focused.

Apparently it is not only me having a really short attention span, but Rathod and Bruna in 2004 (1) have found that participants exert less effort and take less time to respond to questionnaires in an experiment: The time taken to answer the questions of a short questionnaire was significantly longer than the time spend on answering exactly the same questions at the end of a long questionnaire. This indicates that participants think about their answers less and put less effort into the answers if the questionnaire is too long.
However, Brehman et al. (2009) found that participant fatigue does not always bias the results, even if the task is longlasting and requires a lot of concentration.

Four hundred and seventy undergraduate students were asked to answer 20 open-ended questions on a Level of Emotional Awareness Scale (LEAS) test. To measure the participant fatigue, they measured the time the participant took to answer each question and the LEAS score for each question (item). There was no correlation between item number, the time the participant took to answer it, and the LEAS score for each question. Hence, there was no participant fatique, although the task required a lot of effort since the participants must imagine themselves in a situation and then focus on their feelings and describe them.

Apart from quality, quantity is also important in research to ensure that the findings are reliable and generalizable. If only a very small number of questions are asked or participants only repeat a task a very few times, we do not gain enough data and the mean score gets biased because outliers and abnormalities have too much weight.

Scientists should always gain for results that are most representative of the true population and therefore the tasks must have a certain length. Also, participant faigue is not always the case as shown by Brehman et al. (2009). However, other cases have shown that participant fatigue can bias the results and can also be very unpleasant for the participants. Also, a lot of repetitions can lead to other unwanted effects such as the practice effect which can lead to inconsistant results (Steinborn, et al, 2009). Nevertheless, if researchers think that their results get biased by e.g. the fatigue effect, they can still get back to the drawing board and change the number of items or modify their research design:
I think a resting period of about 10 minutes in between testing like in the study by Martin et al. (2006), would already help to minimize participant fatigue. Also, research has shown that even certain room designs can improve people’s well being and attention span (Cohen, 1998). Changes do not necessarily have to be expensive but small things such as provided drinks can already help.
Therefore, participant fatigue might be a bad thing (biasing the results, unpleasant for participants) and should definitely be payed attention to, but with constructive criticism of the research design, it can be minimised and it is not always the source of inconsistance in the findings.


Brehman, D. K., Burns, S. S., Thaler, N. S., Rojas, S. L., & Barchard, K. A. (2009). Fatigue: A Threat to Study Results. Unpublished manuscript, Department of Psychology, University of Nevada, Las Vegas.

Coen, M.H. (1998) Design principles for intelligent environments. Proc. 15th national/10th conf. on Artificial intelligence/Innovative applications of artificial intelligence, 547 – 554.

Martin H. J., Yule V., Syddall H. E., Dennison E. M., Cooper C., Aihie Sayer A. Is hand-held dynamometry useful for the measurement of quadriceps strength in older people? A comparison with the gold standard Biodex dynamometry. Gerontology. 2006;52(3):154–159.

Steinborn, M. B., Flehmig, H. C., Westhoff, K., & Langner, R. (2009). Differential effects of prolonged work on performance measures in self-paced speed tests. Advances in Cognitive Psychology, 5, 105-113. doi: 10.2478/v10053-008-0070-8

Rathod S. La Bruna A, 2005 Questionnaire length and fatigue effects – does size really matter? ESOMAR 

Born to be…

Connellan and his collegues (1980) claim to have “demonstrated beyond reasonable doubt that [sex]differences are, in parts biological in origin.” According to their study, day-old baby boys look longer at mobiles (physical-mechanical object), while day-old baby girls looked longer at human faces (social object). Since neonates (newbors) by definition, have not yet been influenced by social and cultural factors, they conclude that technique is more for guys and emotions and relationships more for girls.

They conducted the study on 102 neonates (58 female, 44 male). Either a face or a mobile (viewing distance 20 cm) was presented to the new borns who were held by their parents, mean age 36.7 hours, then the attentions period in form of “looking time” was rated. The results showed that overall one day old boys paid significantly more attention to mechanical objects and new born girls looked significantly longer at faces.

The findings seem to be plausible since gender inequality is commonly explained by neurological differences, most popularly the notion that the amount of testosterone affects the relative size of the right and left hemispheres of the brain, and of the corpus callosum and that testosterone is produced by the fetus and measurable in the amniotic fluid in which the baby is bathed in the womb. Controversily, prenatal levels vary considerably even across members of the same sex.

However, the main weakness is that the study lacked critical controls against experimenter bias and was not well-designed. Female and male newborns were propped up in a lap and shown, side by side, an active person or an inanimate object. Since newborns can’t hold their heads up independently, their visual preferences might as well have been determined by the way their parents held them. About a third (51/154) of the newborns fell asleep or cried although their parents were around, reflecting the conditions one day old childrens are in. Moreover, the researcher´s own face was the face-stimuli, who might have reacted diffenently to boys and girls, even if this happened unconsciously.

In sum, the results have no application but support the discrimination against the female brain: While males are good at “leadership, decision making and achievement”, females are suited for “Making friends, mothering, gossiping, and ‘reading’ your partner.” A bunch of better designed research (e.g. Benbow, & Stanley, 1980) has shown that most differences concerning technique is the effect of socialisation and expectations.


Benbow, C. P., & Stanley, J. C. (1980). Sex differences in mathematical ability: Fact or artifact? Science, 210, 1262-1264.

Connellan, J, Baron-Cohen, S, Wheelwright, S, Ba’tki, A, & Ahluwalia, J, (2000). Sex differences in human neonatal social perception. Infant Behavior and    Development, 23, 113-118.

Do you exercise more? No, I just think I do…

When expectations translate into behaviour, the placebo effect is thought to occur; not attributed to drugs or remedy but rather attributed to a certain mindset and beliefs. Kirsh and Sapirstein found (1998) that almost 55% of the positive responses of the patients in clinical drug trials were due to the placebo effect. Expectations, beliefs and symbols have a strong physiological effect on people. But how far does this effect apply to the individual? May it apply to a large aspect of their lifestyle, like exercise? Can we think ourselves slim? Does our mindset mediate the connection between exercise and one’s health?

Crum and Langer (2007) studied to which extent physiological benefits associated with exerciseare the result of the placebo effect. 84 female room attendants working in hotels were measured on weight, blood pressure, body fat, waist-to-hip ratio, and body mass index. Half the group were told that their daily job offers good exercise and subsequently satisfies the Surgeon General’s recommendations for an active lifestyle. The control-group was not provided with said information.

Four weeks after the intervention the aforementioned physiological health variables affected by exercise were measured again. Although their daily routine had not changed, the subjects in the informed condition showed a significant improvement in health: They lost an average of 2 pounds, lowered their systolic BP by 10 points, and were significantly healthier as measured by body-fat percent- age, BMI, and WHR.
The results indicate that one’s mind-set inhibits or enhances the health benefits of exercise independently of actual exercise. However, the effect could also be due to a change in intensity in their actions in the duration of their job, therefore providing difficulty in controlling and monitoring genuine results.

Although none of the participants reported engaging in any additional exercise outside of work, the improvement of health may also have been due to a change of diet but this is very unlikely; none of the participants reported to adopt a better, cut-back diet and improve the quality of the food they ate. However, changing behaviour in regards to diet has been found to be very difficult to occur (Deutschman, 2005). It could be further due to a change of behaviour during work; by working harder or more energetically, based on the knowledge that their work can provide good exercise, participants could easily have shown the improves indicated, especially since only females participated, whom are normally keen on losing weight when possible.
The study, conclusively, does not provide the kind of data necessary to make a valid conclusion. A between subject design in a more controlled environment however, may provide more well-rounded data. The study could be repeated with men and women, who normally do not work out, yet are then set to attend daily fitness classes. One group receives the information that the workout is only a weak exercise, which should not lead to significant improvements. The other group of participants should then be told that the exercise is a hard workout, which should lead to significant improvements. Therefore, an analysis of cause-effect relationships becomes possible and consequentially makes the results more applicable.

No matter if the improvement in health is directly or indirectly, it is clear that a change of mind-set on exercise can lead to a significant improvement of health.


Crum, A. J., & Langer, E. J. 2007, “Mind-set matters: Exercise and the placebo effect”, Psychological Science, vol. 18, no. 2, pp.165-171.

Deutschman, A. (2005). Change or die. Fast Company, 94, 53.

Kirsch, I., & Sapirstein, G. (1998). Listening to Prozac but hearing placebo: A meta-analysis of antidepressant medication. Prevention & Treatment, 1, Article 0002a. Retrieved March 7, 2012, from

Men are better at parking than women.. or not?

Everyone knows about stereotypical sex differences: Women can´t play computer games Men can´t cook, women CAN NOT PARK.

However, a study looked at technique, accuracy, and time spent trying to park in and found that women end up with their cars closer to the center of the space, are in more accurate positions before starting each maneuver, are better at finding spaces and are therefore better at parking overall. The study was conducted in the UK on 2500 drivers across 700 parking lots.

It was assumed that women retain information better. The results were published in hundreds of newspapers with headlines such as “A Study finds Women are better at Parking and “It´s official: women drivers are better than men at parking

Controversially, a study, conducted on male and female drivers in Germany, on sex differences in parking ability found that men are better in parking than women.

So. Who is right? Well, the question is, if there is a ‘right or wrong’, a ‘better or worse’, especially considering how controversial the results are.
 An other study revealed how important people’s frame of mind is: Before participants competed a test of shape rotation, they were asked to think about either a family-oriented woman or a man in a position of high power. After thinking about these old-school stereotypically roles, the men performed better than women. However, after thinking about an alfa female, women and men performed comparably. Or other, non-biological differences could be the cause: Research  has shown that some of the male superiority in spatial skill, if existent, is due to their greater exposure to video games.

There are a lot of studies which seem to reveal a significant sex gap and many conclusions are drawn, focussing on innate or biological accounts. Nevertheless, evolutionary or physiological explanations shouldnt be drawn easily. Men and women presumably differ in hormonal and anatomical ways, but vary even more on a very wide range of socialization. For this study on sex differences in parking ability,  role modeling should be taken into consideration. It would probably worse a try to adapt e.g. the trick of imagining non stereotypical roles that were used in the shape-rotation study. Even better, in order to reduce role modeling and therefor a biased result, female participants should have had a look on pictures of female race drivers before they start the test. It would be interesting to see who outperforms who in this study, maybe women and men will finally perform equally.


Feng, J., Spence, I., & Pratt, J. (2007). Playing an Action Video Game Reduces Gender Differences in Spatial Cognition. Psychological Science, 18(10), 850-855.

Ortner, T.M. & Sieverding, M. (2008). Where are the gender differences? Male priming boosts spatial skills. Sex Roles, 59, 274-281.

Wolf, C. (2010). Kognitive Mechanismen beim Einparken Gekonnt Geparkt. Junge forschung. p. 50- 59. Ruhr-University Research School(Bochum).Retrived from:

n.a (2010). Women should be proud they can’t parallel park. Europe Intelligence Wire. Web. 19 Feb. 2012. Retrieved from:

more prescriptions for antidepressants = more depressed people?

The December 30th 2011 issue of The Guardian has an article that identifies that the number of prescriptions for antidepressants increased in the last three years and concludes that a lot more people are depressed.

However, the measurement of the number of prescriptions for a SSRI drug is not a valid way to conclude about the number of people treated with depression or suffering from depression.

The first problem here is that anti depressant drugs are prescribed not only for a treatment of depression but also for many other things e.g. anxiety or eating disorders. Secondly, doctors tend to keep their type of treatment up to date and move away from older drugs and use the newer SSRI drugs instead. Additionally, only the number of prescriptions was measured, not the amount prescribed. The frequency could have increased for the same number of patients e.g. in order to reduce overdose risk. Therefore the number of patients could have remained the same, although the number of prescriptions for the newer SSRI drug has increased.

Exactly the same increase in prescriptions for antidepressants was found in a separate study in Scotland (Munoz-Arroyo, 2006) although, having reviewed the GP consultations dataset, GPs were not making more diagnoses of depression and the the Scottish Health Survey did not show an increase in prevalence of depression. In this case they found an easy explanation by looking at the prescription records of individual patients. The increase in prescriptions was almost entirely caused by a small proportion of patients who retrieved a treatment over longer periods of time, pumping up the overall number.

However, this bit of data is completely ignored. Causal claims are made although studies in the past have shown that this limited view can lead to misinterpretations. There is a difference between being unhappy about a financial situation and clinical depression.

Even if exactly that phenomena is not the reason for the increase in the number of perceptions, researchers and journalists should always consider alternative explanations for what they have found before they make such drastic statements.

Munoz-Arroyo, R., (2006). Exploring potential explanations for the increase in antidepressant prescribing in Scotland using secondary analyses of routine data. British Journal of General Practice. 56(527): 423–428. 

How red gets pink and China the end of the world

In the modern western world, little girls tend to get dressed in pink and boys in blue. A study by Anya C. Hurler and Yazhu Ling was meant to reveal if there are biological components which produce sexual differences in colour preferences or if those differences are only due to cultural imprint.

Her study was conducted on 208 participants who fulfilled a forced-choice colour picking task. The results showed that women seem to prefer reddish-purple colours, while men tend to choose blue-green shades over other colours but are less specific. Hurler and Yatzhu interpreted those results as support for their theory that colour preference is a evolutionary condition since it makes it easier for women as gatherers to recognise berries and changes of mood and for men preferred blue because it indicates good weather and clear water.

However, there are a few serious problems here. The study only supports the sex difference in colour preference, the cause and effect is very vague.

Only preference was measured, not discriminative ability. There is no suggestion that it is easier for women to recognise red.

Their theory relies on other theories, the hunter-gather theory. Although it is likely that there was an evolutionary devotion of labour, it is not proven. It is also unclear why a preference for red should help women recognise mood. Why do women need a preference for pink for doing that and why should men not have this benefit if there is any. Additionally the specialisation on red could also help men hunting since most animals that were hunted for food seem to have reddish-brownish furs.

An other problem in their reasoning is that the pink-blue phenomenon is very young. Pink became famous for children in the 1920s and was for boys. It was not until the 1940s that pink became the colour for girls. Before this, the children of both sex wore white and no specific colours although one would have had the possibilities to colour the clothes.


“There has been a great diversity of opinion on the subject, but the generally accepted rule is pink for boys and blue for girls. The reason is that pink being a more decided and stronger color is more suitable for the boy, while blue, which is more delicate and dainty, is prettier for the girl.”

June 1918 issue of the Ladies’ Home Journal


The participating Chinese sub-culture was meant to reveal a cultural influence in colour preference if present. Indeed, the Chinese participants rated red higher in the study. Since red is very present in China and associated with luck, this might be a hint that the evolutionary cause is not present. However, Hurler and Ling only concluded that sex differences in colour preferences ‘may also be modulated cultural context’. Since the female chinese participants also prefer reddish-purple colours over other colours, they reason that the effect is cross cultural and that it is no adapted behaviour, but they don´t take into account that china is very close to Britain and it is very likely that pink is also connected to girls in china. Therefore an other big problem of the study is that the findings are not generalisable, but only applicable for the modern western world. More research would need to be done to keep the term “cross cultural” up.

The findings of the study were published in several newspapers, including The Times. The findings , in themselves irresolute, are even more biased in those articles. The The Times article for example titled “At last, discovers why blue is for boys but girls really do prefer pink” totally confuses the findings with the hypothesis. The title suggests that the researchers discovered the reason for sex difference in colour preferences but the cause-effect relationship is

only assumed, the findings only reveal the different preference. Additionally, it infers from the actual preferred colour region’reddish-purple’ that the females focus is on pink. The article I much takes the assumptions of the study as proven evidence, leaving out words such as ‘may’, ‘might’ or ‘could’, nevertheless, the article sums up the biases the paper breeds. The conclusion that the division is explained by evolution is as unsupported as my claim that the colour preference is a reminding of the time before clothes were invented: Men were naked outside hunting and gathering so that their skin colour turned blue and the women stayed in the caves next to the fire producing red cheeks. The females were pink, the males blue, leading to mutual attraction.



Hurlbert, A., & Ling, Y (2007). Biological components of sex differences in color preference. Current Biology, 17, R623–R625.


Do mothers who eat chocolate have sweeter (nicer) babies?

Chocolate contains several biologically active components and can therefore have behavioural and psychological consequences, such as the improve of mood. 

In a Psychology Today article, Susan Newman reports about a study on the effect of chocolate consumption during pregnancy on the infant temperament 6 months after birth.

Newman states that the infants of mothers who eat chocolate daily laughed easily and seemingly felt soothed regularly. The mothers observed that their children were not easily scared, laughed easily and were more active. According to Newman, it appears as if something in chocolate protects growing foetus against prenatal stress.

Of course, the biologically active components of chocolate may endogenously affect the neurodevelopment of the infant by promoting characteristics such as activity or they might have protected the infant from inner stress effects before they were born (in the womb). 

However, since other studies have shown that people who eat chocolate show more pro-social behaviour, are more agreeable and feel more joy, it is also possible that the positive temperament is a result of positive (optimistic) mothers and therefore creating a more positive mother-child interaction – resulting in a more positive temperament overall.

There is a sound, validated, biological rationale for expecting a direct influence of chocolate on the foetus but to test this, the study would have needed to analyse the chocolate consumption after delivery (outside of the controlled environment.). In addition to this primary limitation, the lack of specificity the amount and type of chocolate limits researchers. Therefore, such limitations make it difficult to draw a conclusion about causality and hence makes it difficult to apply the results. 


Bruinsma K., Taren D.L. (1999). Chocolate: food or drug?. J. Am. Diet. Assoc., 99, pp. 1249–1256.

Macht, M., Dettmer, D. (2006). Everyday mood and emotions after eating a chocolate bar or an apple. Appetite, 46, 332-336.

Brian P., Sara K., Michael D. ed al (2011). Sweet taste preferences and experiences predict prosocial inferences, personalities, and behaviors .Journal of Personality and Social Psychology, August, 2011