Since many past studies seemed to highlight that children heavily utilised thematic relations whilst developing categories and organising their knowledge which has also been considered as a “judgement error”, an important question now remains as to whether adults continue to make “judgment errors” through their use of thematic relations when making conceptual judgments (Lin, 1996 & Markman 1989) and if so then what is the reason why this occurs? Ultimately is it an error at all?
This essay intends to clarify some of the prior notions by providing evidence from a number of different studies, which have highlighted that adults do tend to make use of thematic links whilst performing cognitive tasks. To begin with contained within this essay will follow an explanation of what it means for items to be thematically linked. In particular this essay will pay attention to the cognitive task of categorisation, which involves judging whether concepts belong within the same category. Ultimately the work of Lin and Murphy in their series of ten studies will be discussed along side the work of Wisneiwski and Bassok in their series of three studies. Both studies have been chosen in order to highlight two interesting opinions regarding the nature of thematic relations used by adult thinkers.
A person whilst performing a cognitive task such as categorisation could use a variety of strategies such as to distinguish an items similarity as a basis for determining whether two or more items belong within the same category. Alternatively a person (adult thinker) could utilize a strategy known as integration (Wisniewski & Bassok 1999). Within the idea of integration the categoriser may concentrate on some features as well as ignoring others. For example when categorizing two objects one might pay attention to features like having different yet complementary roles within the same event or scene which is considered necessary for thematic linking whilst ignoring that they do not share a common property which is considered to be useful for linking items taxonomically.
Hence a common feature that distinguishes a taxonomic category from a thematic category is that a taxonomy has a hierarchical structure, where as a thematic category does not. This structure contains groups of items of the same kind; therefore the members share a common feature or purpose. In addition to this a taxonomy may have a general subject matter such as natural kinds, artefacts or artificially constructed stimuli and this subject matter might consist of a stable structure of members ranging from specialist (super-ordinate), followed by basic to not so well known (sub-ordinate) examples. However a category might also or instead be thematically related; this knowledge usually becomes evident if a concept is taxonomically unrelated. For instance, when a person considers two or more items such as objects, people and other entities that co-occur or interact together in space and time, they could pay attention to the way in which the two items complement each other within a particular scene or event whilst ignoring whether the items share any common properties through class inclusion in other words taxonomic relations. To illustrate the former point: two items such as, chalk and board could be said to share a thematic relation, as they both tend to be used with a classroom. Where as they do not seem to share a taxonomic relation for instance they are not of the same kind nor do they share any common properties. Wisniewski and Bassok highlighted a similar idea within their paper entitled “what makes a man similar to a tie”. In line with the prior example it could be argued that a man is not similar to a tie (the items man and tie do not share a taxonomic relation) as a man is a human and a tie is not, a tie is made out of material and a man is not and so on. Thus if one were to consider that a man might wear a tie or that a tie signifies masculinity then based upon that thought one might consider a man similar to a tie through a thematic relation.
As mentioned earlier the general assumption within the research on adult’s use of concepts is that they tend to use taxonomic relations as a way of distinguishing two or more items. It has since been argued that one of the reasons for this might lie within the design of the studies used to test categorisation strategies. Further to this it has also been proposed by Lin and Murphy that older children and adults might not commonly use similarity but might instead utilise thematic relations as a basis for categorisation. Therefore it might be that both adults and children do make use of thematic relations when making conceptual judgements.
Could it be that the characteristics of the stimuli being considered by the thinker seem to act as a prerequisite for the process to be used regardless of age? In line with this suggestion is another view provided by Wisniewski and Bassok:
“ Often in daily life people are not given task instructions but rather, processing is determined by properties of the stimuli around them.”
Therefore Wisniewski and Bassok might argue that when an adult is considering the properties of two or more stimuli they might ask themselves a number of questions like what makes an item similar to another and what sets it apart from another item? For instance a person (adult) when performing the task of moving house might methodically sort out the things that they are going to take with them in order to make the process of unpacking easier later down the line. The logic applied to this scenario of sorting might differ from person to person depending on the strategy selected at the time by the categoriser. In this example the thinker might assess the items in terms of features like whether they look similar therefore grouping only those items that could be considered as looking the same whilst excluding items with similar uses. Where as another person might assess the items in terms of whether they are used within the same environment. For example ‘knives’ despite having several uses might go in a box with many other kitchen items, as they tend to be stored within the kitchen environment. ‘Forks’ might also be packed alongside ‘knives’ as they too are found within the kitchen and also tend to be used with a knife during the event of eating dinner. Furthermore knives and forks are thematically linked within the event of an eating situation which usually takes place within a kitchen therefore they are not only found but also used within then kitchen.
One of the few experiments conducted specifically to look at the issue of whether adults tend to prefer to choose thematically related concepts to form a category even when a taxonomic alternative exists was carried out by Lin and Murphy. In Lin and Murphy’s series of experiments they used a forced choice category construction tasks to investigate the prior notion. The tasks involved presenting participants with a triad of item names that referred to people, objects and events. At the top of the triangle was the target item, below that were the two other items; one of which was a thematic match and the other the taxonomic match. The participant had to choose which items “goes best with the target to form a category”. In one example the target item was “cat” with a taxonomic match of “lion” and a thematic alternative of “litter box”. Therefore the participant had to choose whether “lion” or “litter box” was the best match to form a category with “cat”. Lin and Murphy found contra to previous findings that almost twice as many adults within their study preferred to construct thematic categories even with the presence of taxonomic alternatives.
In another series of three studies carried out by Wisniewski and Bassok (1999 [3]), the centre of attention was upon the effects of stimulus compatibility in relation to processing. These studies were designed to follow on from the Bassok and Medin (1997 [3]) study. Wisniewski and Bassok (1999 Experiments 1-3 [3]) focused on how well an item matched with another item in relation to the type of process that was selected by the thinker. In the first experiment, which looked at comparison versus integration, Wisniewski and Bassok varied items in four ways for example 1) taxonomically related and thematically related, 2) neither taxonomically nor thematically related, 3) taxonomically related but not thematically related, 4) thematically but not taxonomically related. Participants were instructed either to provide or not to provide a reason as to why they rated the pairs as being similar.
They found that stimulus compatibility had an influence on the particular process selected by the thinker whilst performing a similarity judgment exercise. In addition, Wisniewski and Bassok paid particular attention to the processes of integration and comparison by suggesting that easily alignable items (taxonomic) should invoke the process of comparison where as poorly alignable items (thematic) should increase the chance of items being integrated. Furthermore they found contra to prior opinion that task instructions might not be the over-riding factor responsible for inducing the correct process for the thinker to select. The task required the participant either to provide an explanation or not to provide one whilst considering the similarity within pairs of objects. Participants were often found to integrate thematically related items even though they were instructed to compare for similarity. Where as in an additional (Wisniewski & Bassok 1999, Experiment 3 [3]) study participants compared taxonomically related items whilst looking for thematic relatedness.
Given that adults use of taxonomic categories has received a lot more research compared to thematic usage amongst adults it has thus been assumed that use of taxonomic categories indicates a more powerful and advanced way of thinking (Markman & Callanan, 1983 [2]). A gap seems to exist since the same amount of research has not been committed to the study of adult’s usage of thematic relations. It may be that thematic relations amongst members within a thematic category might provide a basis for the thinker to extend knowledge to other category members. Lin and Murphy subsequently tested this notion in a series of experiments
In essence the evidence discussed within this essay seems to highlight firstly that adults do indeed make use of thematic relations not only within an experimental situation but also in everyday life and secondly the need for more research to be carried out into other areas of adults use of thematic relations in particular social situations. As Markman (1981) suggested “people tend to spend less time on cataloguing objects whilst trying to generate taxonomies to which objects belong and more time on organising their experiences”. Therefore it might seem reasonable to assume that adults who spend time organising their experiences have an increased expertise within the field of relating experiences (scenarios and events) thematically.
Bibliography
References: (the full ref as shown within found bibliography/ should have more refs here)
Bassok, M., & Medin, D. L. (1997). Birds of a feather flock together: Similarity judgments with semantically-rich stimuli. Journal of memory and Language, 36, 311-336.
Inhelder, B., & Piaget, J. (1964). The early growth of logic in the child: Classification and seriation. London: Routledge & Kegan Paul.
Lakoff, (1987)
Lamberts, K., & Shanks, D. (Eds.). (1997). Knowledge, concepts, and categories. Cambridge: MIT Press.
Lin, E, L., & Murphy, G, L. (2001). Thematic relations in adults’ concepts. Journal of Experimental Psychology: General, 130, 3-28.
Markman, E. M. (1981). Two different principles of conceptual organisation. In M. E. Lamb & A. L. Brown (eds.), Advances in developmental psychology (pp. 199-236). Hillsdale, NJ: Erlbaum.
Markman, E. M., & Callanan, M. A. (1983). An analysis of hierarchical classification. In R Sternberg (Ed.), Advances in the psychology of human intelligence (vol. 2, pp. 325-365). Hillsdale, NJ: Erlbaum.
Murphy, G, L. (2001). Causes of taxonomic sorting by adults: A test of the thematic-to-taxonomic shift. Psychonomic Bulletin & Review, 8 (4), 834-839.
Wisniewski, E, J., & Bassok, M. (1999). What makes a man similar to a tie? Stimulus compatability with comparison and integration. Cognitive Psychology, 39, 208-238.
Directly consulted sources: (where the ref was found)
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Lin, E, L., & Murphy, G, L. (2001). Thematic relations in adults’ concepts. Journal of Experimental Psychology: General, 130, 3-28.
Experiments 1-10
Lamberts, K., & Shanks, D. (1997).
Markman, E. M. (1981).
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Murphy, G, L. (2001). Causes of taxonomic sorting by adults: A test of the thematic-to-taxonomic shift. Psychonomic Bulletin & Review, 8 (4), 834-839.
Markman, E. M., & Callanan, M. A. (1983).
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Wisniewski, E, J., & Bassok, M. (1999). What makes a man similar to a tie? Stimulus compatability with comparison and integration. Cognitive Psychology, 39, 208-238.
Experiments 1-3
Bassok, M., & Medin, D. L. (1997)
Inhelder, B., & Piaget, J. (1964)
