Are Opinions Based on Science: Modelling Social Response to Scientific Facts

As scientists we like to think that modern societies and their members base their views, opinions and behaviour on scientific facts. This is not necessarily the case, even though we are all (over-) exposed to information flow through various channels of media, i.e. newspapers, television, radio, internet, and web. It is thought that this is mainly due to the conflicting information on the mass media and to the individual attitude (formed by cultural, educational and environmental factors), that is, one external factor and another personal factor. In this paper we will investigate the dynamical development of opinion in a small population of agents by means of a computational model of opinion formation in a co-evolving network of socially linked agents. The personal and external factors are taken into account by assigning an individual attitude parameter to each agent, and by subjecting all to an external but homogeneous field to simulate the effect of the media. We then adjust the field strength in the model by using actual data on scientific perception surveys carried out in two different populations, which allow us to compare two different societies. We interpret the model findings with the aid of simple mean field calculations. Our results suggest that scientifically sound concepts are more difficult to acquire than concepts not validated by science, since opposing individuals organize themselves in close communities that prevent opinion consensus.Comment: 21 pages, 5 figures. Submitted to PLoS ON

Survey data.

<p>Statements from the EU and Mx surveys that have been considered for this study. The statement labels are ordered from blatant fallacies to obvious facts, according to our judgment. The percentages of agreement (yes) and disagreement (no) for each statement and survey are also shown.</p

Effect of external field.

<p>(a) Relative group size as a function of the external field , where each group is distinguished in terms of both opinion and attitude, as described in the text. Thin lines separate groups and thick lines divide the contributions of experts, ignorants and fundamentalists. (b) Relative group contribution to the average degree of the network as a function of . (c) Fixed point of Eq. (2) (bottom) and associated eigenvalue (top) as a function of the external field. Numerical results are shown as dots, while the corresponding analytical approximations are depicted as lines. (d) Weighted nearest-neighbours’ average opinion for agents in group as a function of , shown as symbols for different opinion groups. The continuous line depicts the analytical approximation of its mean value over all agents. All numerical calculations are averaged over 108 realisations of the dynamics with .</p

Focal versus triadic closure.

<p>Relative group size for experts, ignorants and fundamentalists (a), relative group contribution to the average degree of the network (b), eigenvalue associated with Eq. (2) (c), and weighted nearest-neighbours’s average opinion for undecided agents (d), all plotted as functions of the external field and for rewiring parameter values . All calculations are averaged over 108 realisations of the dynamics. Non-zero values of the rewiring parameter retain the qualitative picture of the case shown in Fig. 2, along with a displacement of the critical point and non-trivial behaviour in the region .</p

Final state of the network for .

<p>Asymptotically stationary state of the dynamics for chosen initial conditions and parameters, as described in the text. Decided agents are represented by red () or blue () circles, and undecided agents by yellow () or black () squares. The right (left) column corresponds to positive (negative) field of increasing magnitude. All calculations were done with , i.e. rewiring with triadic closure mechanism only. The visualisation shows the basic asymmetry of the model: for stronger negative field the community structure is quickly lost and there is an asymptotic growth towards negative consensus, while for growing positive field fundamentalists linger in well-connected communities and ignorants slow down the drive towards positive consensus.</p

Adjusting field strength with survey data.

<p>(a) External field strength as a function of the fraction of agreeing individuals for a rewiring parameter value of . Continuous lines show the model simulations for the same set of parameters as used in Fig. 4. Symbols correspond to for statements in the EU survey, with adjusted values so that the agreement fractions between statement and simulation coincide. (b) The same but with symbols corresponding to statements in the Mx survey. (c) Assigned values for all 15 statements in the EU and Mx surveys, each set in different order according to the statement labels. (d) The same but only for 9 selected statements without cultural content, shown in the same order for both surveys.</p