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Agrociencia
versión On-line ISSN 2521-9766versión impresa ISSN 1405-3195
Agrociencia vol.52 no.5 Texcoco jul./ago. 2018
Socioeconomics
Measurement of public perception of GMOs with a likert-type scale
1 Coordinación Para la Innovación y Aplicación de la Ciencia y Tecnología, Universidad Autónoma de San Luis Potosí. 78210. Avenida Sierra Leona No. 550, Colonia Lomas, Segunda Sección, San Luis Potosí, México. (angeroave@gmail.com)
2 Laboratorio de Género, Salud y Ambiente, Facultad de Medicina, Universidad Autónoma de San Luis Potosí. Avenida Venustiano Carranza 2405, Colonia Los Filtros, San Luis Potosí, México.
3 Facultad de Ingeniería, Universidad Autónoma de San Luis Potosí. Dr. Manuel Nava No. 8, Colonia Zona Universitaria Poniente, San Luis Potosí, México.
The development and commercialization of Genetically Modified Organisms (GMOs) has encouraged the public to learn about their benefits and risks to health and environment. The objective of this study was to evaluate the perception of GMOs in undergraduate and graduate students of the Universidad Autónoma de San Luis Potosí, Mexico. To that end, a Likert questionnaire was applied, consisting of five dimensions and 30 items. The non-probability sampling measured the attitudes related to: disclosure of information, application in agriculture, environmental impact, use of labels, and impact of GMOs on human health. Fifty-five point six percent of the participants considered that the information provided by the institutions is insufficient, and 53.9 % expressed a lack of confidence in the information broadcasted by the media. Fifty-three point two percent of the participants acknowledged that GMOs reduced the use of insecticides and increased the resistance to extreme conditions. The participants said that they were not aware of their environmental impact. Sixty-one percent of the participants considered that labeling products with GM content can allow consumers to choose which one they prefer. The study proved that students are interested in acquiring impartial information about GMOs, their impact on the environment and health, and the relevance of labeling GM products.
Key words: genetically modified foods; consumer perception; Likert scale
El desarrollo y comercialización de los Organismos Genéticamente Modificados (OGM) ha motivado al público a conocer información sobre sus beneficios y riesgos en la salud y en el ambiente. El objetivo de este estudio fue evaluar la percepción de los OGM en estudiantes de licenciatura y posgrado de la Universidad Autónoma de San Luis Potosí, México. Para tal fin, se aplicó un cuestionario tipo Likert, integrado por cinco dimensiones y 30 reactivos. El estudio de opinión no probabilístico midió las actitudes relacionadas con: divulgación de la información, aplicación en la agricultura, impacto en el ambiente, uso de etiquetas e impacto de los OGM en la salud humana. De los encuestados 55.6 % consideró que la información emitida por las instituciones es insuficiente y 53.9 % manifestó falta de confianza en la difusión de la información en medios de comunicación. De los encuestados 53.2 % reconoció los beneficios de los OGM relacionados a la reducción en el uso de insecticidas y la resistencia a condiciones extremas. Los encuestados manifestaron desconocimiento de su impacto en el ambiente. De los encuestados 61 % estimó conveniente el uso de etiquetas en productos con contenido GM para que el consumidor pueda elegir. El estudio evidenció el interés de los estudiantes por conocer más la información imparcial de los OGM, sus impactos en el ambiente y la salud y la pertinencia del uso de etiquetas en productos GM.
Palabras clave: alimentos genéticamente modificados; percepción del consumidor; escala Likert
Introduction
The development of Genetically Modified Organisms (GMOs) is important for the economy, the environment, and society. Therefore, perception studies have included the opinions, needs, requirements, knowledge, and information of the consumer about the topic (Santos-Álvarez et al., 2011; Ueland et al., 2012; Idilfitri et al., 2015).
Perception means the cognitive process through which the person obtains information, interprets it, and generates an attitude based on it (Costa-Font et al., 2008; Santos-Álvarez et al., 2011; Ueland et al., 2012). In the case of GMOs, this attitude depends on how the consumer perceives and weighs the risks and benefits to health, environment, and society (Han and Harrison, 2007; Costa-Font et al., 2008; Martínez-Poveda et al., 2009). Attitudes are developed based on the individual’s knowledge, his or her values, and the reliability and credibility of the information and the institutions that share it (Frewer, 2003; Costa-Font et al., 2008; Martínez-Poveda et al., 2009). Knowledge is directly proportional to the attitude: as knowledge increases, so does the positive attitude, and vice versa (Vecchione et al., 2015).
Differences in media exposure, standard of living, and geographic factors affect the consumer purchasing decisions (Han and Harrison, 2007; Areal, 2012; Frewer et al., 2013). The media affect consumer response and behavior; therefore, a less informed public is generally more exposed to persuasion and variation in their purchasing attitude (Montuori et al., 2012; Jin and Han, 2014). On the contrary, highly-educated consumers have more information and a greater understanding of the topic. Therefore, they are capable of making a better evaluation of the information provided by the media (Han and Harrison, 2007).
Perception is also related to the consumer trust in the institutions and the regulatory policies that are applied to the product (Costa-Font et al., 2008; Frewer et al., 2013). Frewer et al. (2013) proved, by means of an analysis based on regions, that European consumers tend to express less positive attitudes towards GMOs, compared to American and Asian consumers. One of the reasons behind this difference is the lack of trust in legislation and low credibility in regulatory institutions by Europeans (Houghton et al., 2008). Costa-Font et al. (2008) point out that American consumers are more optimistic towards GM products, because, even if they are not fully aware of what they are consuming, they trust government labeling policies. Consumers put greater trust in labeled products, because labels give them some guarantee and credibility that those products have a minimum level of quality and that they can be safely consumed (van Rijswijk et al., 2008). Labeling products with GM content implies both pros and cons; using labels helps to respect the client’s right to know and to decide what he or she consumes (Viljoen and Marx, 2013). However, labeling can also generate a negative perception about these technologies (Botha and Viljoen, 2008).
The mandatory criterion affects the decision to use labels. According to Costanigro and Lusk (2014), a mandatory label that includes the slogan “contains GMO” can generate a negative attitude towards the product in the consumer and prevent its purchase. However, using an optional “does not contain GMO” label, applicable to those products whose content does not include this material, would encourage more favorable attitudes in the consumer.
Rating or attitude assessment scales are the most frequently used method in the development of market or public opinion research (Grover and Vriens, 2006). Likert-type scales are used to measure attitudes, i.e., the emotional predisposition to react coherently, favorably, or unfavorably to people, objects, or ideas (Dutton and Blum, 1968). This type of scales presents statements to which participants answer in the interval from strongly agree to strongly disagree (Komorita, 1963; ten Klooster et al., 2008). Each statement has a weighting: the trend of attitudes of an individual is obtained from the total sum of those attitudes (Komorita, 1963; Dutton and Blum, 1968).
The development of GMOs has generated a debate about their potential benefits and risks to agriculture, environment, and health (Ruane and Sonnino, 2011; Houshyani, 2012; Kos, 2012). In Mexico, studies about the perception of biotechnology and the use of GMOs have taken into account government officials, Non-Governmental Organizations (NGOs), academia, farmers, and other parties (Aerni et al., 2001; Díaz-Pérez et al., 2009; Montesinos-López et al., 2015). Positive perceptions about the economic impact of GM crops, due to the increase in agricultural production and savings in supplies (Aerni et al., 2001; Díaz-Pérez et al., 2009; Montesinos-López et al., 2015), were reported. Concern has arisen over the lack of information about the negative effects on health that might be caused by the excessive use of chemicals, as well as of the long-term effects of GM food consumption (Montesinos-López et al., 2015). Additionally, potential environmental damages were reported when GMOs of culturally important and genetically diverse varieties are used (Aerni et al., 2001). This has been the case of corn in Mexico.
The limited development of studies shows the need for more research related to the analysis of public perception. Therefore, applying a Likert-type scale will allow researchers to detect opinions about the benefits and risks of GMOs. The objective of this study was to evaluate the perception of GMOs in undergraduate and graduate students of the Universidad Autónoma de San Luis Potosí (UASLP), Mexico, with a Likert-type questionnaire.
Materials and Methods
Sample selection and definition of the construct
The study was carried out from March to October 2014, in the Universidad Autónoma de San Luis Potosí (UASLP), San Luis Potosí. An intentional non-probability sampling was used, taking into consideration the particular features of participants, their diverse professional profiles, academic maturity, knowledge of the topic, and how likely they can obtain information. The Likert-type questionnaire (or instrument) was applied to senior undergraduate and graduate (MSc and ScD in Technology and Water Management, and Biomedical Sciences) students who had successfully attended most of the curriculum and whose decision-making capacity and attitude could be better supported. The information was grouped according to the following related areas: Agronomy, Sciences, Health Sciences, Chemical Sciences, Law and Social Sciences, Economy and Commerce, Architecture and Engineering, and Postgraduate Studies.
Review and validation by judges
The review was carried out with the support of a group of three experts (ScD) in the following areas: biotechnology (1), agronomy (1), and molecular biology (1). An initial questionnaire was used to developed this phase, with 40 items distributed in six dimensions. In order to provide the judges with a review criterion, a validation, verification and commenting document was structured, which included the criteria that were analyzed for each dimension (Table 1). In addition, each judge received a review template that allowed him or her to evaluate the relevance of the instrument in the identification of attitudes, correspondence of the item with the evaluated dimension, spelling mistakes, and language used.
Table 1 Dimensions and criteria analyzed using the Likert-type questionnaires.
Dimensión | Criterios |
Divulgación de la información | Difusión de la información |
Credibilidad | |
Aplicación de OGM en la agricultura | Uso de agroquímicos |
Rendimiento | |
Resistencia a condiciones de escasez | |
Impacto en el medio ambiente | Variedades nativas |
Resistencia a insectos | |
Etiquetado | Selección por parte del consumidor |
Consumo de productos con contenido GM | Impactos a la salud |
Vida útil del producto | |
Aspecto económico | Acceso a agricultores |
Piloting
In the piloting phase, the validated instrument was applied to a sample group of 30 students, from different professional areas, in order to analyze its relevance and clarity. In addition, the instrument’s consistency was validated using Cronbach’s Alpha Coefficient. This factor uses minimum and maximum values to determine the consistency of an instrument or to corroborate the interrelation between the items, and the questionnaire’s validity (Oviedo and Campo-Arias, 2005). Two psychologists, with experience in the development of Likert-type scales, supported the assessment of the psychometric properties of the instrument. The data analysis was carried out with IBM’s SPSS Statistics 21 software (IBM, 2012), which enabled the validation of the questionnaire assimilation degree and the relevance of the statements.
Modifications to the questionnaire and final structure
For this phase, the relationship between items and established dimensions was identified, and the relevance of their use in the questionnaire was analyzed. Those items whose focus did not fall under the scope of this study were eliminated; eventually, 30 items and five dimensions were left. The eliminated items were related to the costs and benefits of GM seeds for farmers (this information was not available to the target audience). The evaluation scale was 1 to 5. Five (5) and one (1) were established as the highest and lowest scores for positively structured items; meanwhile, one (1) and five (5) were established as the highest and lowest scores for the negatively structured items (Table 2).
Table 2 Scales for positively (+) and negatively (-) structured items.
Escala | Puntos | |
(+) | (-) | |
Totalmente de acuerdo | 5 | 1 |
Algo de acuerdo | 4 | 2 |
Ni en acuerdo, ni en desacuerdo | 3 | 3 |
Algo en desacuerdo | 2 | 4 |
Totalmente en desacuerdo | 1 | 5 |
Based on the number of items per dimension and on the weighting for each item type, maximum and minimum scores were established according to their final dimension (Table 3). Based on this information, a four-rank scale was finally set as reference for the final interpretation of the results. The scale included the following values: very favorable, somewhat favorable, somewhat unfavorable or very unfavorable.
Table 3 Scores per dimension for attitude measurement.
Dimensión | Puntuación Máxima | Puntuación Mínima |
Divulgación de la información | 25 | 5 |
Aplicación de OGM en la agricultura | 25 | 5 |
Impacto de los OGM en el medio ambiente | 35 | 7 |
Uso de información visible (etiquetas) en productos con contenido GM | 10 | 2 |
Uso de OGM para consumo humano | 55 | 11 |
Completing the questionnaire
Professors and managers were contacted, through verbal or written requests, explaining the purpose of the research, before the questionnaire was actually presented to the participants. The questionnaires were presented in a targeted manner, explaining to the participants the objective of the study, the structure of the instrument, filling instructions, and rating scale according to the participant’s judgement. IBM’s SPSS Statistics 21 program, which facilitates the management of Likert-type scales, was used to develop a database based on this information.
Results and Discussion
The evaluation by judges and piloting was decisive to make modifications to the Likert-type questionnaire. Ten items were eliminated, including economic aspects for the farmer, such as profitability for small and medium farmers, resource use cost, seed costs, and others. Five-hundred and four students (average age: 23 years) were subject to the final instrument, which included 30 items distributed in five dimensions: disclosure of information, application of GMOs in agriculture, environmental impact, labeling products with GMOs, and use of GMOs for human consumption.
Reliability analysis
The consistency analysis, based on the Cronbach’s Alpha Coefficient, establish that, if the coefficient value is lower than 0.70, the consistency is low. In contrast, if the value is higher than 0.9, a redundancy is assumed to exist; in other words, several items are measuring the same element of a construct (Oviedo and Campo-Arias, 2005).
Cronbach’s Alpha Coefficient was 0.756. This indicated that the instrument had an interrelation between the instrument items and the questionnaire validity. Therefore, it was able to consistently measure public perception towards GMOs, throughout this study.
Analysis per dimensions
Dimension: Disclosure of information
The items in this dimension were structured in order to find out which are the attitudes related to: sufficiency and availability of information, trust in the information issued in various media, and citizen participation in the development of related regulations. The representative trend of the dimension with the participation of 383 participants was “somewhat favorable” (77.4 % of the total) (Table 4).
Table 4 Frequency (F) and percentage (%) of general attitudes per dimension.
Actitud | Dimensión† | |||||||||||||
Información | Agricultura | Ambiente | Etiqueta | Consumo | ||||||||||
F | % | F | % | F | % | F | % | F | % | |||||
Muy Desfavorable | 3 | 0.6 | 3 | 0.6 | 3 | 0.6 | 13 | 2.6 | 1 | 0.2 | ||||
Desfavorable | 50 | 10.1 | 38 | 7.5 | 28 | 5.9 | 22 | 4.4 | 46 | 9.6 | ||||
Favorable | 383 | 77.4 | 307 | 61.8 | 359 | 75.3 | 169 | 34 | 395 | 82.8 | ||||
Muy Favorable | 59 | 11.9 | 149 | 30 | 87 | 18.2 | 293 | 59 | 35 | 7.3 | ||||
Datos perdidos | 9 | 7 | 27 | 7 | 27 |
† Información (Information): Disclosure of information. Agricultura (Agriculture): Application of GMOs in agriculture. Ambiente (Environment): Environmental impact of GMOs. Etiqueta (Label): Labeling of products with GM content. Consumo (Consumption): Use of GMOs for human consumption.
In the same dimension, the “somewhat favorable” criterion stood out in all areas knowledge analyzed; the following areas had a +80 % participation: Agronomy (83 %), Chemical Sciences (83 %), Postgraduate (81 %), and Economy and Commerce (81 %) (Figure 1). The analysis per items suggested that information about the advantages and disadvantages of GMOs is indeed available; however, participants showed little faith in the information provided by the media (53.9 % of the participants considered that it was untrustworthy), and the relevant institutions must increase the information available to the public (55.6 % of the participants considered that there is a lack of information).
The trust of the participants in the information provided by the media can be attributed to the segmented approach of some of the communication channels. Consumers should have access to impartial, clear, and complete information, before they decide whether they would use or not GMOs. This will likely improve the attitude towards the topic (Han and Harrison, 2007).
The participants declared their ignorance about the role that the consumer plays within the GMO legislation. Public participation and trust in decision-making and the regulatory framework is very important; therefore, the public must be made more aware of this information and it should be allowed to engage in decision-making through public consultations (Frewer, 2003).
A public consultation process is carried out when an authorization request for planting GMOs in any Mexican region is looked into (DOF, 2005). This type of consultation promotes citizen participation. Citizens are asked their opinion on the topic, which should have technical and scientific basis (DOF, 2005). However, only few citizens are aware of this right. Therefore, decision-makers must analyze the channels that are currently used to spread information.
Dimension: Application of GMOs in agriculture
In this dimension, the “somewhat favorable” criterion stood out as the attitude trend among the 307 participants (61.8 % of the total). The “very favorable” assessment (30 % of the total) ranked second (Table 4). The favorable trend stood out in all areas (50 %) (Figure 2). The participants accepted the benefits of GMOs in agricultural crops. These results match the findings of Aerni et al. (2001). GMOs are an alternative that promotes agriculture and improves agricultural crop yield. Additionally, their capacity to withstand extreme drought or humidity conditions has been recognized.
The favorability criterion obtained in this dimension included the participants’ uncertainty about the effect and potential impact of GMOs in the quality of nearby food and crops. According to Beckwith et al. (2003), this attitude can be attributed to the ignorance of the consequences for human health, for example, the development of potential allergic reactions as a result of eating food with GM content. In the case of the effect on crops, the perceived risks may include potential cross-pollination between GM and non-GM species, pest resistance problems, and unforeseen consequences (Beckwith et al., 2003).
Dimension: Environmental impact
The information provided by the participants in relation to environmental advantages or disadvantages of using GMOs, potential impacts on non-target species, use of agrochemicals, and impacts on soil showed a mostly favorable attitude trend. This criterion was chosen by 359 participants (75.3 % of the total). This trend was followed by the “very favorable” criterion (18.2 % of the total) (Table 4). The score was higher than 70 % in all areas, although the trend was higher among science (82 %) and postgraduate (88 %) students (Figure 3).
The previous findings matched the results of Aerni et al. (2001): the participants approved the use of GMOs as an alternative to solve crop problems (such as pest infestation) and to control the use of insecticides. However, there was great uncertainty regarding the use of GMOs to reduce the application of herbicides, as well as the impact on soil and non-target species (Anderson et al., 2005; Montesinos-López et al., 2015). According to FAO (2001), some unforeseen environmental effects could impact microbial populations in the soil. These populations regulate the flow of N, P, and other essential elements for cultivation. Additionally, the transfer of genetic material to other species is still uncertain (FAO, 2001; Beckwith et al., 2003).
Dimension: Labeling of products with genetically modified content
In this dimension, the participants’ opinion about the relevance of using visible information, such as labels or markers, that declare the GM ingredients included was analyzed. The representative trend of attitudes was “very favorable”, with the contribution of 293 participants (59 % of the total). This attitude was followed by the “somewhat favorable” criterion (34 % of the participants) (Table 4). The “very favorable” criterion stood out in the following areas: Architecture and Engineering (69.7 %), Sciences (64.4 %), Health Sciences (60.3 %), Economy and Commerce (59.5 %), Law and Social Sciences (55.2 %), and Agronomy (50.8 %). In the Chemical Sciences area, the score was higher in the “somewhat favorable” attitude (50 % of the participation), followed by “very favorable” (45.4 % of the participants) (Figure 4).
![](/img/revistas/agro/v52n5//2521-9766-agro-52-05-767-gf9.jpg)
Figure 4 Attitudes per area of knowledge in the labeling of products with genetically modified content dimension.
The trend in attitudes pointed out the importance of labeling of products with GM content. This matched the conclusions reached by Montesinos-López et al. (2015): most participants were in favor of labeling products with GMOs. Those labels do not imply that those products are unsafe. Viljoen and Marx (2013) agree that labeling products with GM content respect the right of the consumers to know what they are consuming and their freedom to choose whether or not to buy the product. Therefore, analyzing the relationship between labeling and consumer trust, with food quality and safety, would be advisable (van Rijswijk et al., 2008).
In Mexico, in certain cases, the Ley de Bioseguridad de Organismos Genéticamente Modificados (Law on the Biosafety of Genetically Modified Organisms) provides for the inclusion of information about food composition in the product’s label. When the product contains components or nutritional properties that are significantly different from conventional products, its label must include the appropriate information (DOF, 2005). The topic is of general interest; therefore, the information channels must be improved and the consumer participation in decision-making must be encouraged. The findings of this study identified the participants’ need to be aware of the composition of GM products. Labeling can provide a visual way to inform the public about GM content.
Dimension: Use of GMOs for human consumption
In this dimension, the participants’ opinion about the potential benefits and risks involved in the consumption of foods with GM content such as the increase in the product shelf life and its vitamin content, and the development of toxins and allergens was recorded. The “somewhat favorable” attitude stood out in the attitude analysis: this criterion was chosen by 395 participants (82.8 % of the total). All analyzed areas showed scores higher than 70 %. The areas which showed a more favorable attitude were: Postgraduate (90.6 %), Sciences (90.2 %), Economy and Commerce (87.8 %), Architecture and Engineering (85.9 %), and Chemical Sciences (81.8 %) (Figure 5).
Favorable opinions mainly took into consideration that this type of food can be an alternative to improve its availability and shelf life. However, participants were uncertain about the advantages or disadvantages of its vitamin content and allergen potential. According to Beckwith et al. (2011), the GMOs’ contribution to food nutritional content is recognized. However, participants voiced their uncertainty about the future potential impacts of GMOs in human health. This lack of knowledge shows that scientific research in the area must be expanded.
Conclusions
The questionnaire used in this study demonstrated the need to improve information channels, to increase the awareness of the benefits and risks to health and environment, and to engage the consumer opinion in decisions about labeling GM products.
Current communication channels are not enough, since 55.6 % and 53.9 % of the participants considered that the information is scarce and unreliable, respectively.
The uncertainty about the potential impacts of GMOs on health and the environment affects the consumer trust and generates precaution attitudes towards its adoption.
Perception studies that use Likert-type scales are a relevant tool to find out and evaluate the opinions of the consumers about the advantages or disadvantages of GM products on health and environment.
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Received: June 2017; Accepted: December 2017