About 10 years ago, a colleague and I compared scientific literacy content in introductory science textbooks(Macias & Macias, 2009). We found that psychology textbooks dedicated an average of about 21 pages to such content; about three times the amount in biology texts and 10 times what was typical for physics and chemistry (see Figure 1). But, as we pointed out elsewhere, this textual advantage may not translate into variations in student knowledge (Macias & Macias, 2018). The purpose of this study was to investigate differences in students’ acquisition of scientific literacy.
To be clear, we do not claim that psychology texts or classes contain more science. It is easy to confuse science literacy and scientific literacy. The former concerns retaining discipline specific knowledge, for example the basic principles of classical conditioning, the phases of mitosis, Ohm’s Law, Avogadro’s number, etc. The latter is nondiscipline specific, involving concepts common to all science such as research methods involved in generating scientific knowledge (Keith & Beins, 2017). Such knowledge includes knowing the differences between evidence and belief, theories and guesses, the importance of falsifiability, parsimony, etc.
In the present study my students and I distributed a modified version of a scientific literacy test created by Wenning (2006) to students in psychology and political science courses. (As a standard core curriculum course, political science provided a range of students with and without general science credit.) We collected 347 useable surveys: 150 students with psychology credits, 138 with general science (but no psychology) credits, and 59 students with no science class credits.
Our first comparison was between students who had taken only one psychology, one general science, or no science courses. Unfortunately, these restrictions generated only 24 psychology, 86 general science and 59 no-science students (see Table 1). An analysis of variance was not significant (no doubt due to the small sample) (F (2, 166) = 1.7; p= .19). However, dividing the literacy scores into three relatively equal groups: high (70% and higher), medium (55-65%) and low (50% and lower) ranges, we found a significantly disproportional distribution (X2 (4) = 10.5; p<.05) with a modest effect size (Cramer’s V = .13) (see Figure 2). Fifty-eight percent of the psychology students scored in the high range. Only 29% and 27% of the general science and no-science participants scored in this same range (see Figure 2).
While these data support the claim that psychology is more likely than general science to produce scientific literacy, this is based on a very small sample. Our next evaluation compared the 150 students who had taken at least one psychology course (many of whom also had general science courses) (Group 1), the 138 students who had taken one or more general science courses (but not psychology) (Group 2), and the 59 students who had not taken any science courses (Group 3) (see Table 1). This comparison did show a significant effect (F (2, 344) = 8.7; p<.001) with a modest effect size (η²= .048). Pair-wise post-hoc comparisons showed a significant effect for Group 1 vs. Group 2 (Scheffe’ = 3.7; p<.01), Group 1 vs. Group 3 (Scheffe’ = 3.1; p<.01), but not for Group 2 vs. Group 3 (Scheffe’ = 0.23) (see Table 2).
Dividing this distribution into high, medium and low ranges also shows a significantly disproportional distribution, virtually identical to that for students with only one psychology or general science course (see Figure 3)(X2 (4) = 27.64; p<.001; with a modest effect size; Cramer’s V=.14.)
A possible confounding issue may be that Group 1 students took more general science courses, and that their higher scores are due to this advantage, not due specifically to psychology classes. As it turned out, Group 1 students did have a very small general science advantage; an average 0.13 more general science classes (1.73 vs. 1.60); this is not a significant difference and the effect size is trivial (Cohen’s d =.09).
In summary, I am confident that this study demonstrates that the traditional emphasis psychology courses place on scientific literacy does, in fact, result in an increased awareness in our students; it really isn’t just the textbooks. However, to demonstrate that this effect is general and not just among community college students, the study does need to be replicated, preferably at baccalaureate granting institutions, especially in capstone courses in various science majors (though the difficulty level of the literacy exam would have to be increased to avoid a probable compression at the top score ranges; see Wenning (2006) for the complete version).
As has been stated in numerous other sources (e.g., Lombardi, 2019; also see Keith and Beins, 2017, for an excellent review), the value of scientific literacy is enormous. Science knowledge grows constantly; no one can maintain currency in what is known. Yet, how scientists determine what is known does not change. An educated citizenry demands this capacity. Scientific illiteracy (such as denial of climate change and the promotion of immunization fallacies) endangers us all.
*The author gratefully acknowledges contributions from student research colleagues: Macy Charpentier, Tyler Taylor and Anna Babb (2016); Samantha Haxton and Alyssa Sturgell (2017); Jannette Williams and Christine Nance (2018); Nathan Martin and Edward Acevedo, (2019) and the assistance from faculty colleagues for allowing us access to their classes: Erin Baribeau, PhD, Robert Castleberry, PhD, Maritza Hogan, PhD, and Damien Picariello, PhD.
References
Keith, K.D. & Beins, B.C. (2017). The Worth guide to scientific literacy: Thinking like a psychological scientist. NY: Worth Publishers.
Lombardi, D. (2019, January). Thinking scientifically in a changing world. Psychological Science Agenda: Science Brief. Science Directorate, American Psychological Association. https://www.apa.org/science/about/psa/2019/01/changing-world.
Macias, S, III, & Macias, D.R. (2009, Winter 08/09). Is Psychology 101 more scientific than other introductory science courses? Yes! The Psychology Teacher Network, 18(4), 3, 14-15. Education Directorate, American Psychological Association. https://www.apa.org/ed/precollege/ptn/2008/11/issue.pdf (PDF, 2.07MB).
Macias, S., III & Macias. D.R. (2018). A comparison of introductory science textbooks: A sampling and content analysis for non-discipline specific scientific concepts. In SAGE Research Methods Cases. Online ISBN: 9781526445940. DOI: http://dx.doi.org/10.4135/9781526445940.
Wenning, C.J. (2006). A framework for teaching the nature of science. Journal of Physics Teacher Education Online, 3(3), 3-10.
