BRAIN & BEHAVIOUR
Draganski (2004) - Laboratory Experiment
Characteristics of Laboratory Experiments:
High control over extraneous variables;
standardized procedures;
often in artificial settings.
Strengths:
Allows for the establishment of cause-and-effect relationships;
high reliability due to standardized procedures.
Weaknesses: Low ecological validity (results may not generalize to real-world settings); potential for demand characteristics
experimenter effects.
How the research method was used:
1. Controlled Environment:The use of MRI scans provided a controlled and objective means of measuring brain changes, enhancing the reliability of the data collected. The juggling practice, while not strictly controlled, was consistent across participants.
2. Repeated Measures Design: MRI scans were conducted at three time points (before, during, and after juggling practice), allowing researchers to track brain changes within the same individuals over time.
3. Random Assignment (partially): While the transcript mentions random assignment, it also notes that the sample predominantly comprised females, which may limit generalizability.
Milner (1966) - Case Study
* **Characteristics of Case Studies:** In-depth investigation of a single individual or small group; longitudinal (often over a long period); rich qualitative data.
* **Strengths:** Provides rich, detailed data; high ecological validity if conducted in a natural setting; allows for in-depth understanding of complex phenomena.
* **Weaknesses:** Limited generalizability due to small sample size; time-consuming and resource-intensive; potential for researcher bias.
* **How the research method was used:**
1. **Longitudinal Design:** The study followed H.M. over many years, allowing researchers to observe the long-term effects of his brain surgery.
2. **Multiple Data Sources:** Data was collected through observations, interviews, and neuropsychological assessments, providing a comprehensive picture of H.M.'s cognitive abilities.
3. **In-depth Analysis:** The unique nature of H.M.'s case (severe amnesia following surgery) allowed researchers to gain insights into the role of the hippocampus in memory.
HORMONES AND PHEROMONES
Romero et al. (2014) - Laboratory Experiment
How the research method was used:
1. Controlled Environment: The interactions between dogs and their owners were observed in a controlled lab setting, minimizing extraneous variables.
2. Quantitative Methods: Urinary oxytocin levels and coded behavioural interactions provided quantitative data to assess the effects of oxytocin.
3. Controlled Manipulation: Dogs were randomly assigned to either oxytocin or placebo groups, allowing researchers to compare the effects of the hormone on behaviour.
Wedekind et al. (1995) - Natural Experiment
Characteristics of Natural Experiments:
Researchers observe naturally occurring events;
IV is not manipulated;
high ecological validity.
Strengths:
High ecological validity;
can study variables that cannot be ethically manipulated.
Weaknesses:
Less control over extraneous variables;
cannot establish cause-and-effect relationships with certainty;
difficult to replicate.
How the research method was used:
1. Naturally Occurring IV: The researchers used naturally occurring variations in MHC genotypes (a measure of genetic compatibility) as the independent variable.
2. Naturalistic Setting: Participants interacted in a relatively naturalistic setting (smelling t-shirts), mirroring real-life mate selection processes.
3. Observation of Preferences: The researchers observed female participants' preferences based on the naturally occurring variations in male MHC genotypes.
GENETICS AND BEHAVIOUR:
Caspi et al. (2003) - Correlational Study
Characteristics of Correlational Studies:
Examines the relationship between two or more variables;
does not manipulate variables;
cannot establish cause-and-effect.
Strengths:
Can examine relationships between variables that cannot be ethically manipulated;
relatively inexpensive and less time-consuming than experiments.
Weaknesses:
Cannot establish cause-and-effect relationships;
Correlation does not equal causation;
potential for confounding variables.
How the research method was used:
1. Measurement of Variables: Caspi et al. (2003) likely measured relevant variables (e.g., genetic predisposition, environmental factors, and behavioural outcomes) through questionnaires or other assessments.
2. Correlation Analysis: Statistical methods were used to determine the strength and direction of the relationship between the measured variables.
3. Interpretation of Findings: The researchers interpreted the correlation coefficients to draw inferences about the relationships between genetic factors, environmental factors, and the behaviour in question. It's crucial to note that any correlations found do not imply direct causation.
Kendler (2006) - Twin Study
Characteristics of Twin Studies:
Compares concordance rates for monozygotic (identical) and dizygotic (fraternal) twins;
used to estimate the heritability of traits;
relies on self-report or other assessments of traits and behaviours.
Strengths:
Can provide estimates of heritability;
helpful in identifying genetic contributions to behaviour.
Weaknesses:
Assumes equal environments for twins (may not always be true);
limited generalizability;
challenges in disentangling genetic and environmental influences;
relies on self-report or other assessments, which can be prone to bias.
How the research method was used:
1. Comparison of Twin Pairs: Kendler's 2006 study likely compared concordance rates for a specific behaviour or trait in identical and fraternal twins, especially when investigating whether heritability was dependent on the sex of the twins.
2. Heritability Estimation: By comparing the concordance rates, researchers can estimate the proportion of variance in the trait attributable to genetic factors.
3. Environmental Influence Assessment: Differences in concordance rates between MZ and DZ twins could indicate the extent to which environmental factors influence the behaviour or trait.