Key Studies for the IA

Travis DixonInternal Assessment (IB)

The following list of studies and related theories can be a good starting point for conducting your IA.

Disclaimer: This list contains studies that have been conducted successfully by students in the past. However, it’s the responsibility of teachers and students to assess the suitability of specific studies for the internal assessment. The most important thing when choosing a study is to know how its results are related to a theory or model.


Important News: As of May 2021, “effects” are no longer considered appropriate background theories or models. So Mozart effect, Stroop effect, misinformation effect, etc., need to be explained by a theory or model.

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Don’t forget we have a special YouTube playlist for all of our videos on the IB Psych IA.

The Laundry Study

  • Study: The effects of prior knowledge on comprehension and memory by Bransford and Johnson (1972) (Link)
  • Theory: Schema theory
  • Info:  This classic study looked at how giving context and activating prior knowledge can help us understand and remember new information. It is a great study to use on the exams to support schema theory.
  • Tip: The originally studied comprehension and recall – you should choose one DV for your replication.

You can find more studies on pg. 352 of our textbook. Chapter 7 has everything you need in a lesson-by-lesson approach for the IA.

Smartphone Distractions and Cognition

  • Can you study with your smartphone? These studies are more relevant than ever as >95% of teenagers have smartphones.


    • Smartphone notifications and working memory (Aharony and Zion, 2019)(Link)
    • The mere presence of a smartphone and working memory (Ward et al. 2017)(Link)
  • Theory: Cognitive load theory (Sweller, 1988). This theory posits that effective learning requires considering the relationship between the cognitive demands of a learning task (its cognitive load) and our working memory capacity.
  • Info: Aharony and Zion found that when people were getting smartphone notifications their performance on working memory tests was reduced. Ward et al. found a similar effect even when the phones were turned off – merely having a smartphone in one’s presence reduced working memory scores.
  • Tip:
    • Some studies have used a wordfind as a way to measure “cognitive performance” when distracting with cellphones. If you find it difficult to measure working memory capacity, this could be an option.
    • While it might be tempting to replicate studies on Nomophobia and anxiety, remember that “Any experimental study that creates anxiety, stress, pain or discomfort for participants is not permitted.” (Guide, p70).

The Pen is Mightier than the Sword

  • Study: Handwriting vs. Typing by Mueller and Oppenheimer (2014)(Link)
  • Theory: There are a number of relevant theories to apply here, including:
    • The encoding hypothesis
    • The external storage hypothesis
    • The levels of processing model could (Read the full original summary of the model here).
    • Disfluency theory
    • The theory of embodied cognition
    • Cognitive load theory (if laptops with notifications and open tabs become a source of extraneous cognitive load)
  • Info: This study aimed to see which note taking method was more effective for learning, long hand notes (pen and paper) or using a laptop.
  • Tip: In the original experiment they let participants choose how they took notes. Do not do this for your IA as the student-researchers need to be the ones manipulating the IV. For the theory, choose the one you think best explains the results of the original study.

Mr Dixon’s Top Tip: Don’t do the Stroop effect – it is very difficult to do properly, especially as it requires linking to an original theory. However, IF your teacher approves then it is possible to do.

Music and Cognition

  • Studies: The Mozart Effect by Rauscher et al. (1993) (Link), Liked vs. Disliked music (Perham and Vizard, 2010)(Link). “Keep calm and pump up the jams.” (Marti-Marca et al. 2020); Music v No Music (Cokerton, Moore and Normal, 1997)(Link).
  • Relevant theories (choose one):
  • Info: One study found that participants who listened to Mozart music actually performed better on cognitive tasks (spatial reasoning tests) than those who didn’t. However, it has failed to be successfully replicated, which has sparked a debate over the existence of the Mozart Effect. Mart-Marca et al. found that listening to music that increased positive mood improved attention.
  • Tip: Whichever study you use, the most important thing is that you can clearly link the aim and results to a background theory or model (or hypothesis). “Effects” by themselves are not enough.

How good is your memory?

  • Study: The duration of short-term memory by Peterson and Peterson (1959) (Link)
  • Theory: Multi-store model of memory (Atkinson and Shiffrin)
  • Info: This study tested the duration of short-term memory by having participants remember trigrams whilst counting backwards at varying intervals. They found our short-term memory without rehearsal is about 20 seconds.
  • Tip: Simplify the original experiment to only two conditions to make it easier for the inferential analysis.

Our teacher support pack has everything you need to get top marks in the IA. Download a Free preview from

Google and Memory

  • Study: Google effects on Memory by Sparrow, Liu and Wegner (2011) (Link)
  • Theory: Transactive memory theory (Wegner, 1985).
  • Info: This study tested the effects of external storage systems of information (e.g. google) on memory.
  • Tip: The original experiment had multiple conditions – you can simplify it to two conditions (one IV) and one DV.

Loftus and Palmer used to be here. However, I have removed it because I think there are better options available. One problem with Loftus and Palmer is that it’s difficult to explain fully using schema theory and reconstructive memory. It’s not impossible, but it’s much more difficult than other options. Also, in order to best explain reconstructive memory you need the second study (Loftus and Palmer themselves admit this in their paper) about broken glass, but this only gathers nominal data so it’s not ideal for the IA. In short, it’s possible to do this study but I recommend others unless you really, really want to do it. If so, read this blog on Tips for Loftus and Palmer.

TV and Working Memory

  • Study: The effects of TV on working memory (Lillard and Peterson, 2011) (Link)
  • Theory: The working memory model
  • Info: This study looked at how different types of TV (SpongeBob vs. Caillou) would affect working memory capacity.
  • Tip: Be sure to think carefully about what this study is saying about working memory.

Fake it til’ you make it

  • Study: Facial expressions and mood by Kleinke et al. (1998) (Link)
  • Theory: The Facial Feedback Hypothesis
  • Info: This study aimed to see if physically mimicking a smile (without any emotion of happiness) can increase someone’s mood. Smiles are forced by holding a pen between the teeth.
  • Tip: One tricky thing with this study is if you use the PANAS scale. You can simplify this measurement to have a change in mood and focus only one positive or negative moods.

Remember that actually in the new IB Psych curriculum (first exams May 2019) the theory is actually more important than the study. In fact, you could even conduct the IA successfully without replicating a study but by designing your own experiment that tests a theory. However, it is strongly advised that you replicate an original study, simplify it (if necessary) to two conditions and make sure you understand how the study relates to a theory or model. 

Heuristics and Biases (e.g. Anchoring Effect)

  • Study: Anchoring bias and guessing Gandhi’s age by Kahneman and Tversky (Link to summary)(Link to original); could also use ascending/descending maths problem (1x2x-…x8) or (8x7x6….x1).
  • Theory: The dual processing model of thinking and decision making
  • Info: This study aimed to see if we can manipulate people’s thinking by using the anchoring effect. This is when you give someone a random number and it can influence their guess about the value of an unrelated item.
  • Tip: It’s best to try to use the dual processing model of thinking and decision making as the background theory or model to explain the phenomenon of the anchoring effect. Previously “effects” such as anchoring effect, Mozart effect or the misinformation effect have been acceptable as background theories to the studies replicated for the IA. However, as of May 2021 they are no longer accepted.

The following were added in February 2021

Fortune Favours the Bold – Font and Memory

  • Study: The effects of difficult to read fonts on memory (Diemand-Yauman et al. 2011)(Abstract)(You can also read a summary here – note that they say 2010 but it’s the same study).
  • Theories:
    • Disfluency theory
    • Levels of processing model (Read the full original summary of the model here)
  • Info: In their second experiment, the researchers actually conducted their study on high school students in Ohio, USA. They changed PowerPoint slides and worksheets used by teachers to be in difficult to read fonts (e.g. Haettenschweiler, monotype corsiva or comic sans italicized). The control condition used the regular fonts selected by the teacher. Students in the disfluent condition scored higher in class assessments than in the control conditions.
  • Tips: Be careful with how you link the study to the model. The fonts do not affect semantic processing, but they do require deeper processing in an alternative way. The fonts are “desirable difficulties” – what psychologists call anything that adds cognitive difficulties to learning tasks to improve learning.

And the award for the best journal article title goes to…

Weapon Focus

  • Study: Weapon focus and memory reliability (Loftus, Loftus and Messo, 1987 Full Article).
  • Theory: Theoretical explanations include the “unusual item hypothesis” (read more), Easterbrook’s (1959) cue-utilisation hypothesis or the “automatic capture of attention” hypothesis (Read more about both these hypothesis in Pickel et al.’s 2006 study). (Edit: The “weapon focus” is not a theory or model, so you need a theory to explain the effect).
  • Info: People have reduced memory of a scene when a weapon is present because their attention is focused on the weapon. Loftus et al. tested this by showing participants a slide show of a robbery where the robber shows the cashier a gun in one condition, or a check in another.
  • Tips: The weapon can be manipulated in a photo using photoshop. Avoid using images that are gruesome or violent for ethical reasons.

Colour and Cognition

  • Studies:
  • Theory: Elliot and Maier’s (2012) color in context theory (Read more) and/or Goldstein’s (1942) colour theory (Read more). The researchers hypothesized that “…different associations related to red versus blue color can induce alternative motivations. Specifically, red, because of its association with dangers and mistakes, should activate an avoidance motivation, which has been shown to make people more vigilant and risk averse.” This is why they will make fewer mistakes on a task like a memory test.
  • Info: In Rehta and Zhu’s second study, “A set of participants completed the detailed-oriented task (i.e., a memory exercise) presented on computers with red, blue, or neutral background color. They studied a list of 36 words for 2 min and were asked to recall as many words as they could after a 20-min delay.” The results showed that those in the red condition remembered more.
  • Tips: If you’re doing the above study, simplify it to two conditions.

Remember you don’t have to replicate an existing study. You could read about theories of colour’s influence on memory and design your own experiment to these theories (however, this is not for the faint hearted as it’s much, much easier to replicate a study). This review of studies on colour and memory also has some good studies you could choose to replicate. Other studies have also tested the effects of colour on memory. E.g. McConnohie found that slide background colours affect memory (see this study and others in this review.) or that room colour can affect SAT scores (Read more).

Colour and Stress

  • Study: The effects of shown the effects of colour on reducing stress (Saito and Tada, 2007)(Abstract).
  • Theory: Elliot and Maier’s (2012) color in context theory (Read more) and/or Goldstein’s (1942) colour theory (Read more). This article (a student’s thesis) explains how Goldstein’s theory and studies showed that red has a stimulating effect on human behaviour so it might increase stress levels.
  • Info: In this study, “…color photographs of natural scenery were shown to an experimental group (n = 10), while the same images in black and white were shown to a control group (n = 10).” Stress was measured by taking cortisol and the colour images reduced stress whereas black and white increased stress.
  • Tips: You can use an adapted version of the Perceived Stress Scale to measure the DV, rather than collecting cortisol samples. Based on the theories above, it could be useful to manipulate red instead of black and white and compare with natural colours to test the effects on stress.

The Effort Heuristic

  • Study: The effects of perceived effort on the rating of quality (Kruger et al. 2010)(Download here.)
  • Theory:  Kahnemann’s dual process theory is a good theory to explain this effect (Read more on Wikipedia).
  • Info: In this study, “Participants read and evaluated the poem ‘‘Order’’ by contemporary poet Michael Van Walleghen. Half were told that it took Van Walleghen 4 h to compose the poem (low-effort condition), and half were told that it took 18 h (high-effort condition).” The participants were then asked “…how much they liked the poem on a scale from 1 (hate it) to 6 (it’s OK) to 11 (love it).” They then “…assessed the ‘‘overall quality’’ of the poem on a scale from 1 (terrible) to 6 (OK) to 11 (excellent)” before they were finally asked to indicate “how much money the poem would be likely to fetch (in US dollars) if sold to a poetry magazine?” Those in the high effort condition rated the poem higher than the low effort condition.
  • Tips: The original experiment had three conditions – the poetry experiment (#1) is probably the easiest to conduct. Simplify it to one dependent variable. If you come up with a good reason for your choice, explain it in your materials.

Me, Myself and Memory

  • Study: The influence of self-reference on memory (Rogers, Kuiper and Kirker, 1977)(Full Study)
  • Theory: This has been named “the self-reference effect” (see this review for more information). Levels of processing theory (Read the full original summary of the model here) or schema theory is potential theoretical explanation for the self-reference effect (Read more on Wikipedia)
  • Info: Participants “…rated 40 adjectives on one of four tasks. This involved presenting a cue question, followed by 1 of the 40 adjectives. Subjects answered yes or no to the cue question as it applied to the adjective.” (See Table 1 below from the original study for the four conditions). They were then given a blank piece of paper and 3 minutes to write down as many as they could remember. The results showed the self-referencing condition had the best recall.
  • Tips: Below is an image that gives some information about how they manipulated self-referencing with a simple yes or no question in relation to 40 adjectives. Choose two of the conditions below to compare – self-reference and one other so you have a clear IV.

Articulatory Suppression

  • Study: The effects of reciting words out loud on recall (Landry and Bartling, 2011)(Abstract)(Full Study)
  • Theory: The working memory model (Baddeley and Hitch). This article gives a good explanation of articulatory suppression and working memory.
  • Info: When participants are trying to remember a list of words presented visually on a screen, they’ll perform worse when having to be saying irrelevant things at the same time. This is called “articulatory suppression.” (You can read about some more possible experimental procedures to use in this article, too).
  • Tips: When linking this study to the model, be sure to focus specifically on the role of the phonological loop and how articulatory suppression affects it. I’ve searched high and low for the full study but I can’t find it. I’d be appreciative if anyone finds it and could send it to me.

First Impressions 

  • Study: forming impressions of someone’s personality (Asch, 1946). (Download Full Study)
  • Theory: Edit: I previously stated that  “the primacy of warmth effect” was a possible theory to use. (Read more). However, effects are no longer accepted as “theories or models” for the IA so you’ll need a specific theory to explain this effect.
  • Info: “In the classic warm-cold study (Study I), participants were either exposed to a trait-list containing warm or to a trait-list containing cold, keeping all other traits identical between groups. Participants then wrote down their impression of the target person (open-ended measure), selected which traits from a trait-pair list were most applicable to the target (trait-pair choice measure), and ranked the original traits according to importance for their impression (ranking measure).” Those with “warm” in the list rated the person more favourably than those with “cold” in the list. (Read more)
  • Tips: To test the primacy of warmth effect, make sure “warm” or “cold” is at the top of the list of adjectives.

Visual Noise and Memory

  • Study: The effects of visual noise on memory (Quinn and McConnell, 1996)(Abstract)
  • Theory: The working memory model
  • Info: When participants are trying to use visual mnemonics to remember words, watching visual static interferes with memory recall more so than if they are using simple rote learning memorization techniques (e.g. repeating the word over and over). The results suggest that “…the VSSP (visuospatial sketchpad) is specifically susceptible to irrelevant dynamic visual noise. This irrelevant task has no significant effect on rote learning tasks, which presumably are handled in the phonological loop.”
  • Tips: The full original article can be difficult to find online, which is something to bear in mind if you want to read more about the study. You can use “static noise” clips on Youtube for the interference (example).

Word Length Effect

  • Study: The effects of word length of memory (Baddeley, Thomson and Buchanan, 1975)(Full article)
  • Info: This study found that participants could remember monosyllabic words better than polysyllabic words (E.g. those with eight syllables). This is in stark contrast to Miller’s hypothesis that “…the capacity of short-term memory is constant when measured in terms of number of chunks, a chunk being a subjectively meaningful unit.” This study challenges this hypothesis.
  • Theory: Miller’s hypothesis and/or the multi-store model of memory (capacity of the short-term store).
  • Tips: Be warned – this study is more complicated than it looks because the link between the hypothesis and the study can be difficult to comprehend. It’s also different in that it’s challenging a background theory, whereas most studies for the IA are supporting one.

Here…hold my coffee

  • Study: Does holding a warm cup of coffee increased mood? (Williams and Barge, 2008 (Full article).
  • Theory: Bowlby’s attachment theory (Read more). The original study cites Bowlby’s theory as one explanation for the results – because of early life experiences with a trustworthy parent or caregiver “…a close mental association should develop between the concepts of physical warmth and psychological warmth.” This idea is supported by neurobiological studies of attachment that have “…added further support for the proposed link between tactile temperature sensation and feelings of psychological warmth and trust.” ((Williams and Barge, 2008 (Full article).
  • Tips: This is a difficult study to conduct because it’s time consuming – each participant has to be studied individually and it requires many practical considerations (that’s a lot of cups of coffee to make!).

Exercise and Memory

  • Study: Effects of exercise on memory (Labuan and Etneir, 2011)(Full article)
  • Theory: The Yerkes-Dodson Law (an inverted U hypothesis of arousal and performance)(Wikipedia).
    • An alternative is the reticular-activating hypofrontality theory, but my understanding of this complex theory is that it explains implicit memory, not explicit memory (Read more)
  • Tips: This is not a good study to conduct online and it is time consuming and involves many practical difficulties. It would require highly motivated participants who were willing to give up a lot of time and effort.

(Dis?)Honourable Mentions: Be VERY careful before doing these.

  • Glanzer and Cunitz: Read more about this study for the IA here or watch the video here.
  • Loftus and Palmer: Read more here or watch here.

Got a suggestion? Pop it in the comments. This list will be continually updated.