Psychology Core Studies

?
  • Created by: michelle
  • Created on: 25-04-13 11:08

Loftus and Palmer: Experiment 1

Aim: to investigate the accuracy of memory and to see if estimates given by ppts about the speed of vehicles in a traffic accident would be influenced by the wording of the question asked

Method:
Laboratory experiment
Participants: 45 students, split into 5 experimental groups
Ppts were shown seven film clips of different traffic accidents. The clips were originally made as part of a driver safety film.
After each clip ppts were given a questionnaire asking them to describe the accident and then answer a series of specific questions.
One was the critical question: 'About how fast were the cars going when they hit eachother?' One group of ppts were given this question. The other four groups were given the verbs 'smashed', 'colided', 'bumped' or 'contacted'.

Results: the mean speed estimate was higher if the verb sounded harsher (smashed had the highest speed estimate)

1 of 32

Loftus and Palmer: Experiment 2

Aim: to investiage the effect of leading questions on memory. In particular to see if such questions crewated a response-bias or if they actually alter a person's memory respresentation

Method: Participants: new group of 150 students
Part 1: ppts were shown a one-minute film clip which contained a four-second multiple car accident. They were asked a set of questions including the critical question about speed. There were three groups.
Group 1 - 'How fast were the cars going when they smashed into eachother?'
Group 2 - 'How fast were the cars going when they hit into each other?'
Group 3 - asked no question as it was a control group
Part 2: one week later they returned. They were asked some further questions inc. 'Did you see any broken glass?' (which is a leading question). There was no broken glass in the film.

Results:
Part 1: same as from experiment 1
Part 2: ppts in the 'smashed' condition were more likely to think that they saw broken glass

2 of 32

Evaluating Loftus and Palmer

The Research Method
This was a laboratory experiment, meaning that it has high control over extraneous variables, so cause and effect and be inferred. However, it has low ecological validity as it is not in a naturalistic environment so the findings can be hard to generalise

The Sample
American students were used in this study. Students are not representative of the general population in a number of ways. Importantly they may be less experienced drivers and therefore less confident in their ability to estimate speeds. This may have influenced them to be more swayed by the verb in the question. However, it was quite a large sample increasing the generalisability.

Data Collected
The data collected was quantitative. This makes the results easy to analyse, but it doesn't give much depth.

3 of 32

Baron-Cohen et al. (autism)

Aim: to investigate if high functioning adults with autism or Asperger syndrome would be impaired on a theory of mind test called the ‘Reading the Mind in the Eyes Task’

Method:
Three group of ppts were tested
Group 1: participants with autism/ AS, of normal intelligence, 13 males and 3 females
Group 2: 50 'normal' adults (no history of mental illness), age matched (control group)
Group 3: participants with Tourette syndrome (TS), 8 males and 2 females (control group)

Ppts were given the following tasks (tasks 3 and 4 were control tasks given to group 1 and group 2 only did task 1)
Task A: Eyes Task, 25 forced choice questions about emotion expressed in a persons eyes. Tested basic and complex emotions. eg. attraction or repulsion, relaxed or worried. 
Task B: Strange Stories Task, used to validate results from Eyes Task
Task C: Gender Recognition of Eyes, a control
Task D: Basic Emotion Recognition Task, a control, ppts asked to identify emotions in whole faces

4 of 32

Baron-Cohen et al. (autism) - Results

Autism/AS - mean score = 16.3
Normal - mean score = 20.3
TS - mean score = 20.4

This shows that the normal and TS groups performed identically, while ppts with autism got significantly lower, showing that they have a lower ToM

Normal males - mean score = 18.8
Normal females - mean score = 21.8

This shows that females performed significantly better than the males, meaning they have a more advanced ToM

Conclusion
Results seem to provide evidence of ToM deficits in adults with autism or AS

5 of 32

Evaluating Baron-Cohen et al. (autism)

The Research Method
This study was a quasi-experiment because the IV (autism versus normal) was not something controlled by the experimenter. This allows for cause and effect but it is done in a laboratory meaning it lacks ecological validity.

6 of 32

Savage-Rumbaugh et al.

Aim: to study human language capabilities in pygmy chimpanzees

Method:
the report focuses on 2 pygmy chimpanzees named Kanzi (aged 30-47 months) and Mulika (aged 11-21 months) and compares them to 2 common chimpanzees named Austin and Sherman.
K&M learned to use lexigrams by watching through observation and also through natural communication with the experimenters rather than being specifically trained. The lexigrams were a symbol system consisting of geometric symbols and brightened when touched and spoke in a synthetic voice. K was exposed to the use from the age of 6 months as he watched interactions between his mother (Matata) and her keepers.
They lived in a naturalistic enviornment, a 55-acre forest. They had to collect their own food.
A record was kept of K&M's vocabulary use during the period of this report indicating correctness and whether it was spontaneous. When they used a lexigram indoors on the computer it would be automatically recorded. Outdoors the record was made by hand.
Reliability of the observations was also formally tested at the end to rule out the effect of cueing.

7 of 32

Savage-Rumbaugh et al. - Results

Untutored gestures
K&M naturally used gestures to communicated. They were usually more explicit than those used by A&S eg. when M wanted a balloon blown up she placed it in a persons hand and then pointed to the persons mouth and pushed the balloon towards their mouth.

Use of Lexigrams
K used the lexigrams when his mother went away (2.5 years). He immediately had fair vocab. M began using symbols at 12 months, much earlier than K.
At about 14 months M begans using a number of lexigrams appropriately, her new words over the next few months were milk, surprise, peanut, hotdog, mushroom, melon, banana, blueberry and more
Neither K or M had difficulty identifying a lexigram when it was in a new position

Associative useage
Both chimps started using a new term in an associative context first

General observations
Both K&M made generalisations beyond the meaning of a word eg. used tomato to refer to round red fruits

8 of 32

Savage-Rumbaugh et al. - Results (2)

Progress
In total, Kanzi required 46 words and Mulika 37.

Combinations
K's multisymbol expressions appeared quite early, within the first month of lexigram usage. In total, over 17 months, K produced 2,540 nonimitative combinations plus 265 which were prompted or partially imitated, and all but 10 were judged to be appropriate and understandable, but 764 were only produced once. Nim (chimp trained to use human language) produced 19,000 combinations during a similar time. K's were more likely to relate to games eg. 'chase bit person.' while Nims were more likely to relate to food.

Imitation
15% utterances were imitation and 80% were spontaenous

Formal tests
K&M did well on the formal tests from the start. A&S were initially confused. K&M could select photographs when prompted with the lexigram, and vice versa, and could also when promted with the spoken word. They struggled when the word was produced by the synthesiser.

9 of 32

Evaluating Savage-Rumbaugh et al.

The Research Method
This research method could be described as a case study and a lab experiment. Case studies provide a lot of depth into individuals, but it is hard to generalise the findings.

The Sample
Various chimpanzees were used in this study, belonging to different species. This makes it easier to generalise to findings to other species of chimps. However, the sample was very small reducing the generalisability.

Representativeness
Each chimp may not have been representative of his/her own species, and may have had certain unique characteristics eg. Nim seemed more interested in food than Kanzi, who talked about games.

Ethical Issue
Part of the process of teaching language to an animal is to enculturate them into the human world. This is unethical as an animal should be in their natural habitat. They were also enclosed in a forest, and despite it being as naturalistic as it could be, it was not fair on the chimps. However, they did not display any signs of trauma.

10 of 32

Samuel and Bryant

Aim: to see if younger children would cope better with Piaget's conservation task if they were asked only one question rather that two questions pre and post-transformation

Method:
252 children from Devon, aged betwen 5 and 8.5, split into 4 age groups; 5,6,7 and 8 yrs old
Each group was subdivided into 3 task groups: standard (2 q's asked), one question asked or fixed array (one question but no transformation)
Each child was tested 12 times - 4 times on each 3 materials (mass, number and volume)

Conservation studies
One example is carried out with some counters. The child is shown two equal rows of counters. The adult asks, 'Which one has more counters?' and the child replies that they are both the same. Then, in full view, the adult spreads out one row of counters. The adult now asks the same question.
A second example is the child is shown two identical glasses with an identical amount of liquid in them. The adult asks, 'Which glass has more water?' and the child replies that they are both the same. Then the adult pours one of the glasses into a longer thinner shaped glass. The adult then asks the same question.

11 of 32

Samuel and Bryant - Results

Results:
Table showing mean number of errors made for each child.

Age                                 Condition
                 Standard      One question      Control
5               8                   7                         9
6               6                   4                         6
7               3                   3                         5
8               2                   1                         3

Altogether there were 3 IV's in this experiment, the results were...

Age: older children made fewer errors
Conditions: children made fewest errors when shows the transformation and asked only one question
Materials: children made fewer errors on the number task and most on the volume task

The results indicate that failure on the traditional 2-question task may be at least partly due to being asked 2 questions rather than because they cannot conserve.

12 of 32

Evaluating Samuel and Bryant

The Research Method
This study is a lab experiment. This lacks ecological validity, but there is high control over extraneous variables.

The Participants
The participants were aged 5 to 8.5 years and there were 252 of them. One issue is that children are more 'suggestible' than adults. They are more likely to respond to researcher's cues because they are more uncertain of themselves. This is called demand characteristics, leading to unvalid results. However, it is a very large sample which increases generalisability.

Ethics
One ethical issue is that the child cannot give informed consent, it comes from the parent/guardian. Another ethical issue is psychological harm, the investigator may distress or decieve the child which could lead to long-term effects.

13 of 32

Bandura et al.

Aim: see if learning that took place in one situation would be generalised to other situations

Participants: children from a university nursery school (Stanford in California)
36 boys and 36 girls, aged between approx. 3 to 5 years. Mean age was 4.5 years.

Procedure:
1. Modelling: children watched a model playing with toys
2. Aggression arousal: the children briefly played with attractive toys but were made to stop
3. Delayed imitation: children were observed playing with toys

Experimental groups:
1. Observed an aggressive model (24 ppts)
2. Observed a non-aggressive model (24 ppts)
3. No model (control) (24 ppts)

Each group was subdivided into 4 groups: boys watching the same sex model, boys watching the opposite sex model, girls watching the same sex model and girls watching the opposite sex model (making a total of 8 experimental groups each with 6 subjects).

14 of 32

Bandura et al. (2)

IV's:
1. Behaviour observed (aggressive vs. non-aggressive)
2. Sex of the role model (same sex vs. opposite sex)
3. Gender of child

DV:
1. Observation of imitated actions 

The observers recorded what the child was doing every 5 seconds for 20 minutes. Responses were recorded in the following categories:
1. Imitative aggression responses (eg. any physical or verbal aggressions which were imitated)
2.Partially imitative responses (eg. mallet aggression - uses mallet on other toys)
3. Non-imitative aggressive responses (eg. punches Bobo doll, aggressive gun play)

Controlling aggressiveness
In order to ensure each group containted equally aggressive children, ratings were done of the children beforehand by an experimenter who knew the child well. On the basis of these ratings the subjects were arranged in triplets and assigned at random to one of the three groups.

15 of 32

Bandura et al. - Results

Complete imitation
Children in the aggressive condition imitated many of the models' physical and verbal behaviours, both aggressive and non-aggressive. In contrast, the children in the non-aggressive condition displayed very few of these behaviours, 70% of them had 0 scores.
Non-imitative
The aggressive group displayed more non-imitative aggression than the non-aggression group, though the difference was small.
Non-aggressive behaviour
Children in the non-aggression condition spent more time playing non-aggressively with dolls than children in the other groups.

Gender effects

  • boys imitated more physical aggression than girls but the groups didn't differ in terms of verbal aggression
  • the were some evidence of 'same sex effect' for boys but not for girls
  • the male models had a greater influence in general than the female models 

In all conditions children behaved aggressively but children only displayed imitative aggression when the model was aggressive.

16 of 32

Evaluating Bandura et al.

The sample
The subjects were young children from one middle-class US nursery school. There were 72 ppts. This means that the sample wasn't representative, and lacks ecological validity because it cannot be generalised to other places.

Ethical issues
The ppts were children and they were asked to witness aggressive behaviour.This means fully informed consent was not gained from the children, the parents had to give consent. Exposure to aggressive behaviour could also influence their behaviour in the future, which does not comply with the ethical issue of protection from harm.

Demand characteristics
Were the ppts imitating the models actions or was this behaviour due to demand characteristics? The results may not be valid.

17 of 32

Freud

Aim: to report the findings of the treatment of a five-year-old boy for his phobia of horses and test his theory on infantile sexuality and the Oedipus complex

Participant: a 5 year old boy called Little Hans who was aged between 3 and 5 during this case study

Procedure: Hans' father recorded events and conversations of Little Hans and sent these regularly to Freud. Both Freud and the father offered interpretations of his behaviour.  

Part I. Hans' early life

  • Before Hans was 3, he started to take an interest in his widdler. He got pleasure from touching it and also from excretion. 
  • His mother caught him playing with his widdler and warned him, 'If you do that, I shall send you to the doctor to cut off your widdler.' This lead to a castration complex. Hans also felt sexual desire for his mother.
  • Hans wished death towards his father and baby sister. He would hit his father and then kiss the spot that he hit.

Sources of anxiety: his mother, his father (he viewed him as a rival) and his sister (he wished she was dead)

18 of 32

Freud (2)

The phobia starts
When Hans was 4.5 he developed a fear that a horse would bite him. Freud explained the links:
1. Hans heard his father warn his daughter that a white horse might bite her is she touched it
2. His mother told him that it would not be proper if she touched his penis - Hans asked her to touch his widdler once when she was drying him after a bath
3. He was afraid his mother may leave him because she dissaproved of his request
4. Horses represented his father
5. His father told him that women have no widdlers. This would lead Hans to think that her widdler was cut off and so his widdler would also be cut off

Further horse anxieties
Fear of horses pulling heavily ladeb carts or a bus. Hans recalled an occasion when he was walking with his mother and they saw a horse pulling a bus fall down and kick its legs about.

  • Hans secretly wished his father would fall down dead
  • Hans had become preoccupied with bowel movements ('lumf'). Lumf in the toilet made a similar noise to the horse falling
19 of 32

Freud (3)

The Plumber
Hans was in the bath and a plumber replaced his behind and his widdler for larger ones.
Hans wanted a big widdler and behind like his father and was identifying with his father.

Fantasises
The dream about giraffes - 'in the night there was a big giraffe in the room and a crumpled one; and the big one called out because I took the crumpled one away from it. Then it stopped called out; and then I sat on top of the crumpled one.' Hans' father perceived that the big giraffe was him or his penis and the crumpled one was Hans' mother or her genital organ.
This scene was a replay of mornings; Hans would come into their bed and Hans' father would warn his mother not to let him sit on her

Criminal fantasies - Hans dreamt of smashing windows in a train with his father. This represented doing something forbidden to his mother which his father was doing

Father fantasy - Hans had an ongoing fantasy about having his own children and how he was going to look after them. He played an imaginary game and told Hans' father that he was the grandaddy. This lead Freud to conclude that Hans had overcome the Oedipus complex. After this he managed to go all the way to the park and no longer feared horses.

20 of 32

Evaluating & Discussing Freud

Support for Freuds theory of sexuality

  • Hans was interested in his widdler
  • Hans had a wish to be close to his mother and to engage in sexual relations with her (Hans asked her to touch his widdler)
  • Hans' father was his rival whom he wished dead, but he also loved deeply (Hans would hit him and kiss the spot) 

Understanding phobias

Freud explained phobias as the conscious expression of repressed anxieties.
Hans' phobias were triggered by real events but represented unconcious anxieties created by conflicts over his feelings towards his mother and father 

Evaluation
The reasearch method
This study was a case study, meaning there was only 1 participant. This makes it hard to generalise the findings as it is not representative

The reasearch technique
The observations were obtained by Hans' father meaning some of the recording may have been subjective. However, it gives a great insight into Hans' life which was naturalistic. 

21 of 32

Maguire et al.

Aim: to investigate whether changes could be detected in the brains of London taxi drivers and to further investigate the functions of the hippocampus in spatial memory

Participants: 16 healthy, right-handed male licensed London taxi drivers. The taxi drivers were compared with the scans of 50 healthy right-handed males who did not drive taxis
All of the participants had been licensed London taxi drivers for more than one and a half years
All of the taxi drivers were described as having healthy general medical, neurological, and psychiatric profiles. 

Procedure: data was collected using structural MRI scans and then these scans were analysed using 2 techniques:
1. VBM (voxel-based morphometry).VBM identified differences in the density of grey matter in different parts of the brain. Grey matter lies on the surface of the brain and also deep inside in structures such as the hypothalamus and hippocampus. It is most dense in neutral connections and therefore associated with higher order thinking. 

2. Pixel Counting. Hippocampal volume was calculated using a well-established pixel counting technique. The pixels were counted in the images produced by the MRI scans.Total hippocampal volume was calculated by adding up the pixels from each slice of the hippocampal region and multiplying this by the distance between adjacent slices.

22 of 32

Results & Explanations & Evaluation of Maguire

Results
The first main findings of the research were that the posterior hippocampi of taxi drivers were significantly larger relative to those of control subjects and that the anterior hippocampal region was larger in control subjects than in taxi drivers.

The second main finding was that hippocampal volume correlated with the amount of time spent as a taxi driver (positively in the right posterior and negatively in the right anterior hippocampus).

Explanations

Maguire et al. argue that this study demonstrates the plasticity of the hippocampus in response to environmental demands.
They argue that the posterior hippocampus stores a spatial representation of the environment and that in the London taxi drivers the volume of the posterior hippocampus expanded because of their dependence on navigation skills. 

Evalutation

The research method
This was a quasi-experiment, meaning the experimenter couldn't manipulate the IV. This means it is harder to establish a relationship. However, is it not as artificial. 

23 of 32

Dement & Kleitman

Aim: to investigate the relationship between eye movements and dreaming

Participants: 9 participants, 7 males and 2 females. 5 were studied intensively, while only a small amount of data was collected on the others

Procedure: the participants were studied under controlled laboratory conditions, whereby they reported to the laboratory just before their usual bedtime. They were asked to eat normally but to avoid caffeine or alcohol on the day of the study. The participants went to bed in a quiet, dark room. The experimental sessions were repeated many times.
Electrodes were attached around the participants eyes to measure electrical activity and hence eye movement (using EOG) and attached to the ppts scalp to record brain waves (using EEG) as a measure of depth of sleep.
At various times during the night ppts were awoken by a bell. They were either awakened during an REM (rapid eye movement) period or at varying times during NREM. On average ppts were awoken 5.7 times a night and slept for 6 hours. 
The ppts were instructed to speak into a recording machine near their bed stating whether they had been dreaming, the content of the dream and if they had been dreaming whether they were dreaming for 5 or 15 minutes.

24 of 32

Dement & Kleitman - Results

Three approached to investigating dreams were used:
1. Eye movement periods and dream recall: high incidence of recall of dreaming during REM periods, and low incidence during NREM periods.
When ppts were awoken during deep NREM sleep they sometimes were rather bewildered and reported that they must have been dreaming but couldn't remember the dream.

2. Length of REM periods and subjective dream-duration estimates: ppts were 82% correct in estimating whether REM activity lasted for 5 or 15 minutes. There was also a correlation between the duration of REM activity and the number of words used to describe a dream.

3. Eye movement patterns and visual imagery of the dream: were linked, for example, horizonal eye movements linked to a dream about two people throwing tomatoes at each other and very little or no movement linked to dreams about watching something in the distance.

This study shows that dreaming is accompanied by REM activity. 

25 of 32

Evaluating Dement & Kleitman

The research method
This study could be considered to be a lab experiment because it took place in controlled conditions. This lacks ecological validity because it isn't the normal environment that the ppts slept in, so dreaming patterns may have varied to normal life. However, it has high control over extraneous variables

The sample
The sample was quite small and there were only 2 women. This lacks representativeness meaning its hard to generalise the findings. 

26 of 32

Sperry (split brain)

Aim: to study the psychological effects of hemispheric disconnection in split-brain patients, and to understand how the right and left hemispheres work in 'normal' individuals

Participants: 11 patients who suffered from severe epileptic seizures which could not be controlled by medication. They had all undergone hemisphere deconnection.

Method: tasks were carried out in laboratory conditions, using specialised equipment and were highly standardised. The tasks all involved setting tasks separately to the two hemispheres.

One of the tasks involved asked participants to respond to visual information. This involved blindfolding one of the participants eyes and then asking them to fixate with the seeing eye on a point in the middle of a screen. The researchers would then project a stimulus on either the left or right hand side of the fixation point for less than 1/10 of a second.
As language is processed in the left hemisphere, when a stimulus is presented to the left visual field of a split-brain patient they should not be able to name the stimulus.

Another of the tasks involved asking patients to respond to tactile information. This involved presenting a stimulus to one of the hands of a split-brain patient so the participant could not see the stimulus and then asking the participant to name it. If the stimulus is presented to the participants left hand the participant should not be able to name it. 

27 of 32

Sperry (split brain)

Aim: to study the psychological effects of hemispheric disconnection in split-brain patients, and to understand how the right and left hemispheres work in 'normal' individuals

Participants: 11 patients who suffered from severe epileptic seizures which could not be controlled by medication. They had all undergone hemisphere deconnection.

Method: tasks were carried out in laboratory conditions, using specialised equipment and were highly standardised. The tasks all involved setting tasks separately to the two hemispheres.

One of the tasks involved asked participants to respond to visual information. This involved blindfolding one of the participants eyes and then asking them to fixate with the seeing eye on a point in the middle of a screen. The researchers would then project a stimulus on either the left or right hand side of the fixation point for less than 1/10 of a second.
As language is processed in the left hemisphere, when a stimulus is presented to the left visual field of a split-brain patient they should not be able to name the stimulus.

Another of the tasks involved asking patients to respond to tactile information. This involved presenting a stimulus to one of the hands of a split-brain patient so the participant could not see the stimulus and then asking the participant to name it. If the stimulus is presented to the participants left hand the participant should not be able to name it. 

28 of 32

Results & Evaluating Sperry (split brain)

  • If a projected picture is shown and responded to in one visual field it is only recognised again if it appears in that visual field
  • If visual material appeared in the right visual field, the patient could describe it in speech and writing as normal
  • If the same visual material is projected to the left visual field then the ppt says he did not see anything or there was just a flash of light on his left side
  • If then asked to use his left hand to point to a matching picture or object in a collection of pictures/objects, the ppt points to the item he just insisted he couldn't see

These results confim that the right hemisphere cannot speak or write, and the left hemisphere controls all language

Evaluating
The sample
11 participants is a very small sample, however there may not be very many split-brain patients available to study. The small sample also enabled Sperry to gain more in-depth data.

Ecological validity
The findings of the study would be unlikely to be found in a real life situation because a person with severed corpus callosum who had both eyes would be able to compensate for such a loss.

29 of 32

Milgram (obedience)

Aim: to investigate what level of obedience would be shown when participants were told by an authority figure to administer electric shocks to another person

Participants: 40 males aged between 20 and 50 years, recruited by a newspaper and direct mail advertisement which asked for volunteers to participate in a study of memory and learning at Yale University. Volunteer sample. They were offered $4.50 to participate

Procedure: A rigged lottery resulted in a confederate being the learner, and the ppt being the teacher. Learner and teacher were taken to the experimental room where the learned was strapped into an 'electric chair apparatus'.
The ppt was given a shock of 45v to be convinced of the authenticity.
The teacher (ppt) was asked to read a series of word pairs to the learner, and then read the first word of the pair along with four terms. The leaner had to indicate which of the 4 terms was originally paired with the first word.
For each wrong answer, the teacher would increase the shocks by 15v. The shock generator went from 15 to 450v.
The learner made no protest until 300v when he pounded on the wall. After 315 he pounded again but went silent after that.
The experimenter was trained to give a series of standardised 'prods' if teacher turned for advice eg. 'The experiment requires that you continue.' or 'You have no other choice, you must go on.'

30 of 32

Milgram (obedience) - Results

  • All 40 of the participants obeyed up to 300 volts at which point 5 refused to continue.  
  • Four more gave one further shock before refusing; two broke off at the 330 volts level and one each at 345, 360 and 375 volts.  
  • Therefore, a total of 14 participants defied the experimenter, and 26 obeyed.  
  • Overall, 65% of the participants gave shocks up to 450 volts (obeyed) and 35% stopped sometime before 450 volts.
  • During the study many participants showed signs of nervousness and tension. Participants sweated, trembled, stuttered, bit their lips, groaned, dug fingernails into their flesh, nervous laughing fits (14 out of 40 participants).
  • Full-blown uncontrollable seizures were observed for three participants.
  • With few exceptions, participants were convinced of the reality of the situation

Why did they obey?

  • Location of study was at a prestigious university 
  • Subjects felt obligated because they were paid
  • The subject was ensured that no real damage would be done
31 of 32

Evaluating Milgram (obedience)

The sample
The subjects were US males and volunteers. This reduces representativeness because there were no females and only a certain type of person would volunteer. However, there would be a lower drop out rate because people actually chose to participate in the study

Ethical issues
Ppts were decieved and many suffered from emotional distress. This can question whether the ppts were protected from harm. However, the ppts were all debriefed afterwards to ensure they would leave the laboratory in a state of well-being

Ecological validity
The experiment took place in a lab which reduces the ability to generalise to real life situations. However, there was high control meaning cause and effect could be inferred. 

32 of 32

Comments

Anthony

Report

Thanks so much i've been looking everywhere for something like this

MrsMacLean

Report

Just brilliant, thank you!

Jasmine

Report

Thank you!

Similar Psychology resources:

See all Psychology resources »See all Core studies resources »