Your Brain on Ecolabels
Published on: April 26 2023
Ecolabels are symbols or certifications that are displayed on packaging to indicate that the products they contain meet certain environmental criteria. From a marketing strategy perspective, they might influence consumer purchasing decisions in several distinct ways. For example, ecolabels can in principle serve to raise awareness about environmental issues and encourage consumers to make more environmentally conscious purchasing decisions. They might also increase consumer trust in the product and manufacturer, especially when they are awarded by third-party organizations that have expertise in environmental standards, implying that the products displaying them have been rigorously tested. Display of ecolabels might also convey a competitive advantage at the shelf, at least among consumers who prioritize environmental sustainability and who use such labeling to guide their purchase decisions.
Despite the promise of ecolabelling, several factors can undermine the actual effectiveness of this practice. Many consumers may not be aware of what a particular ecolabel represents or may not understand the specific criteria that was required to receive a third-party certification. Consumers might also find the inherent complexity of such labeling to be confusing, especially given the wide variety of different labeling schemes that have appeared in the marketplace and the fact that assessing the environmental impact of a product is in itself a complicated multidimensional problem. Ecolabelling might also inadvertently signal that a product might have more premium pricing, which in turn could make it less attractive in the minds of a cost-conscious shopper. And finally, ecolabels might also activate some degree of “green skepticism’ is more wary consumers who lack trust in such demarcations.
Past consumer research has served to highlight such limitations. For example, a survey conducted across the EU evaluated the explicitly stated attitudes of consumers towards such labels and concluded that “sustainability labels currently do not play a major role in consumers’ food choices, and future use of these labels will depend on the extent to which consumers’ general concern about sustainability can be turned into actual behavior” (1). Other survey-based research studies have suggested that consumers who claim to have environmentally-friendly attitudes also claim they do not rely on such cues in the marketplace when they are unfamiliar and that most consumers are price sensitive and don’t want to pay more for products with sustainability-related labelling (2). And survey-based studies that have employed causal modeling techniques find that the impact of ecolabelling on purchase intent for ostensibly “green” products reflects an interaction between the a priori attitudes of participants towards ecolabelling and environmental concerns in general and the specific credibility conveyed by any particular label in question (3).
Despite the promise of ecolabelling, several factors can undermine the actual effectiveness of this practice. Many consumers may not be aware of what a particular ecolabel represents or may not understand the specific criteria that was required to receive a third-party certification. Consumers might also find the inherent complexity of such labeling to be confusing, especially given the wide variety of different labeling schemes that have appeared in the marketplace and the fact that assessing the environmental impact of a product is in itself a complicated multidimensional problem. Ecolabelling might also inadvertently signal that a product might have more premium pricing, which in turn could make it less attractive in the minds of a cost-conscious shopper. And finally, ecolabels might also activate some degree of “green skepticism’ is more wary consumers who lack trust in such demarcations.
Past consumer research has served to highlight such limitations. For example, a survey conducted across the EU evaluated the explicitly stated attitudes of consumers towards such labels and concluded that “sustainability labels currently do not play a major role in consumers’ food choices, and future use of these labels will depend on the extent to which consumers’ general concern about sustainability can be turned into actual behavior” (1). Other survey-based research studies have suggested that consumers who claim to have environmentally-friendly attitudes also claim they do not rely on such cues in the marketplace when they are unfamiliar and that most consumers are price sensitive and don’t want to pay more for products with sustainability-related labelling (2). And survey-based studies that have employed causal modeling techniques find that the impact of ecolabelling on purchase intent for ostensibly “green” products reflects an interaction between the a priori attitudes of participants towards ecolabelling and environmental concerns in general and the specific credibility conveyed by any particular label in question (3).
This situation is further complicated by the fact that there exists a well-documented gap between the intentions that people explicitly espouse about making more sustainable consumption choices and their actual actions in such regards. To better understand the factors that underlie this discrepancy, a growing number of researchers have been employing indirect, or “implicit” testing methods to probe consumer attitudes in the sustainability arena beyond those revealed by explicit self-report. Motivations for this shift beyond traditional approaches to attitude assessment stem in part from the assumption that implicit methods are less likely to be contaminated by prosocial response biases, and from the notion that such methods can more sensitively detect associations and emotional responses that might impact decision-making through non-conscious mechanisms. Such indirect methods that don’t depend on explicit verbal reports may entail measures of overt behavior such as eye movements or speeded reaction-time judgments, and/or measures of physiological changes in response to key marketing stimuli. Studies utilizing such indirect measurements have begun to provide additional insights into the impact of ecolabelling on consumers. Let’s dive into to those.
On the more pessimistic side, in 2018 there was a widely publicized research study from the packaging industry (4). That study was conducted in a marketing lab that included a simulated grocery store environment, and a representative sample of retail shoppers. A decent subset of the shoppers reported that sustainability issues were important considerations for them when making purchase decisions. Those shoppers completed a shopping task where they were given a grocery list and were required to fill a basket by deciding among competing alternatives. The research team created a sustainability logo with an associated grade (A-Sustainable, B-Efficient, and C-Average) and created packaging designs for products in diverse categories such as frozen food, snacks, pasta, and OTC medical supplies. Some of those packages were affixed with the sustainability logo to signal each item’s relative environmental sustainability.
Before sending them on their respective shopping journeys, the researchers fixed head-mounted eye tracking devices on the heads of the shopper so that data on the shopper’s direction of gaze could be captured while they inspected shelves and packaging. And then the participants were sent off to shop. The researchers were thus able to measure whether the sustainability logos were an object of gaze fixation during the shopping adventure, and in turn infer whether those logos may have impacted purchase decisions.
The headline that was promoted in conjunction with the results obtained in the study was not subtle: “Consumers don't notice on-pack sustainable messaging, study finds more education needed around sustainability claims” (5). The researchers reported that they found that 92% of participants never fixated on the sustainability logos when examining packages in the store, nor did those logos disproportionately affect participants’ rate of first fixation, nor did they impact simulated purchase decisions.
What are we to make of such findings? That logos suggesting product sustainability may be worthless? That conclusion may be premature – other results indicate that there is more going on than such a disheartening outcome would suggest. For example, another recent eye-tracking study (6) that examined eco-labels on food products found that potential gaze capture and extended dwell time on such elements (as well as their impact on consumer preference) was influenced by manipulations of the size, language and graphic design of the labels -- manipulations that weren’t examined in the study described above. The existence of such effects serves to highlight the importance of pre-testing design elements and overall package presentation to optimize the impact of ecolabelling efforts.
On the more pessimistic side, in 2018 there was a widely publicized research study from the packaging industry (4). That study was conducted in a marketing lab that included a simulated grocery store environment, and a representative sample of retail shoppers. A decent subset of the shoppers reported that sustainability issues were important considerations for them when making purchase decisions. Those shoppers completed a shopping task where they were given a grocery list and were required to fill a basket by deciding among competing alternatives. The research team created a sustainability logo with an associated grade (A-Sustainable, B-Efficient, and C-Average) and created packaging designs for products in diverse categories such as frozen food, snacks, pasta, and OTC medical supplies. Some of those packages were affixed with the sustainability logo to signal each item’s relative environmental sustainability.
Before sending them on their respective shopping journeys, the researchers fixed head-mounted eye tracking devices on the heads of the shopper so that data on the shopper’s direction of gaze could be captured while they inspected shelves and packaging. And then the participants were sent off to shop. The researchers were thus able to measure whether the sustainability logos were an object of gaze fixation during the shopping adventure, and in turn infer whether those logos may have impacted purchase decisions.
The headline that was promoted in conjunction with the results obtained in the study was not subtle: “Consumers don't notice on-pack sustainable messaging, study finds more education needed around sustainability claims” (5). The researchers reported that they found that 92% of participants never fixated on the sustainability logos when examining packages in the store, nor did those logos disproportionately affect participants’ rate of first fixation, nor did they impact simulated purchase decisions.
What are we to make of such findings? That logos suggesting product sustainability may be worthless? That conclusion may be premature – other results indicate that there is more going on than such a disheartening outcome would suggest. For example, another recent eye-tracking study (6) that examined eco-labels on food products found that potential gaze capture and extended dwell time on such elements (as well as their impact on consumer preference) was influenced by manipulations of the size, language and graphic design of the labels -- manipulations that weren’t examined in the study described above. The existence of such effects serves to highlight the importance of pre-testing design elements and overall package presentation to optimize the impact of ecolabelling efforts.
Moreover, it is important to also note that there is a variety of evidence from the cognitive and behavioral sciences indicating that symbols that are familiar and especially those that have been reinforced in the past tend to be preferred and to automatically capture attention. Yet the shopping journey that was created for the mobile eye-tracking shopper study was one involving purchasing decisions in an unfamiliar store, made for unfamiliar products, on which previously unfamiliar sustainability symbols had been affixed. That situation is not reflective of the world we live and habitually shop in. And there is a variety of additional data from the field of consumer neuroscience which indicates that more familiar ecolabels can in fact automatically capture attention and engage consumers. For example, one recent laboratory study (7) used electroencephalographic (EEG) measures to gauge consumer responses when presented with food images that either were associated with ecolabels that indicated sustainable sourcing versus equivalent images without such labeling. That study found that the labelled images were associated with improvements in EEG metrics related to processing fluency and positive emotional valence, and that these differences from the non-labeled images were associated with higher explicit ratings of purchase intent.
Another such study used functional magnetic resonance imaging (fMRI) to measure differences in brain activity while consumers were evaluating products that were or were not labelled with a highly familiar “organic” logo (8). The food products that were labeled for organic sourcing elicited a greater activation of the Nucleus Accumbens (NAcc) component of the reward network (an area associated with preference and reward anticipation) when they were first presented, and then on average were preferred in choice decisions over alternatives lacking such logos. Moreover, the brain activity differences were observed to be greater in participants who reported greater actual day-to-day organic food consumption, suggesting that the symbols may have been particularly salient and relevant to them.
A similar study examined the impact of “fair-trade” logos on the value the brain calculates for products (9). The researchers found that the highly familiar fairtrade logo increased NAcc activation when they were initially presented. Items which also elicited an increased willingness-to-pay were additionally associated with greater activation of the ventromedial prefrontal cortex, an area reliably activated in processes of involved with subjective valuation. Such results provide compelling evidence that when familiar ecolabels are placed on familiar products, they may in fact help to trigger positive associations and increase engagement in the minds of consumers.
Given the growing awareness that consumer choice has a critical impact on greenhouse gas emissions and potential climate change, there has been a concomitant growth in the number of studies examining how consumers process information about the relative carbon intensity of their purchase behavior, including efforts to better understand the impact of related ecolabelling. The Implicit Association Test (IAT) is a computerized reaction-time based research tool for uncovering automatic associations and motivations (10). One group of researchers (10) examined explicit attitudes to the magnitude of carbon footprints associated with a variety of consumer products (as measured with tools such as feeling thermometer and Likert scale ratings), and contrasted those observations in the same participants with a specialized version of the IAT which compared the categories of high and low carbon footprint products with the attributes ‘good’ and ‘bad’. Overall, both explicit and implicit measures strongly suggested that most participants had more positive feelings towards low carbon footprint products. However, while both types of explicit measures were highly correlated across participants, neither displayed a significant correlation with results from the IAT measure. Which in turn suggests that the IAT was indexing a qualitatively different attitudinal process from that indexed by the explicit tests.
This difference appears to be reflected in the fashion by which individuals respond to carbon footprint ecolabelling on packages. In a follow-up study (12) the researchers combined such explicit and implicit measures of attitudes towards carbon footprint information with eye tracking of the participants whose gaze was monitored while they studied images of product packaging that included carbon footprint information and labelling. In this instance the strength of the implicit positive association towards low carbon footprint products was found to be predictive of how quickly participants first directed their gaze at the carbon footprint package labelling, a relationship that was not observed for either of the explicit attitude measurements. Such results suggest that carbon footprint ecolabelling can capture the attention of consumers (at least those implicitly predisposed to prefer low carbon footprint products), whereas measures of explicitly expressed attitudes about the personal importance of carbon footprints appear to be relatively irrelevant for understanding actual consumer behavior.
Related research has examined how consumers respond to ecolabelling that describes the energy efficiency of consumer electronic products. One such study used eye tracking to better understand the impact of affixing a European Union (EU) mandated energy label to imagery and information describing large household products that consumers were asked to choose among (13). When the energy label was included in the display the researchers found that participants spent more time directly considering energy-related information in the product description, especially when cued to consider energy efficiency as part of their product choice. Despite this overall attention effect, the labelling did not appear to help participants to integrate energy information across the product description or to meaningfully impact product choice, shortcomings that the researchers noted could be perhaps overcome by research on improving the label design and changes in policy efforts to better educate consumers on the information content the labelling seeks to convey.
In the US, the well-known “Energy Star” ecolabel is often affixed to consumer products to convey that the product has been certified to meet minimal efficiency standards set by the US Environmental Protection Agency. Unlike the mandatory EU scheme, whether or not to seek Energy Star labeling is up to the manufacturer, and requires that they demonstrate that products which include such labelling are in fact more energy-efficient than similar products lacking certification. One recent study (14) employed fMRI methods examine the neural responses of study participants while they considered choices between light bulb products with or without Energy Star labeling. As with the fMRI studies of organic and fairtrade labeling described above, the ecolabelled options resulted in greater activation of the NAcc, a type of response typically associated with positive affect and increased purchase intent. The researchers also found that the product/label combinations that elicited greater NAcc activation in the laboratory study were also preferred in a nationwide survey study, suggesting that such labeling might promote sustainable purchases by automatically activating implicit positive emotional responses.
This conclusion is consistent with our own internal research on ecolabelling where we used CloudArmy’s cloud-based ReactorTM reaction time testing platform to conduct an “evaluative priming” study of the Energy Star label. This type of implicit response test is based on the notion that attitudes that have a strong association with an “attitude object” (e.g. a word or picture that represents the target of the attitude) can be automatically activated by presentation of the attitude object (cf. 15). Automatic activation of an attitude can inhibit or facilitate processing of subsequently presented adjectives that have positive or negative connotation. In the study we conducted, responses primed by the Energy Star label were found to be significantly positively associated with such adjectives as “trust”, “efficient” and “for me”. That is, such findings suggest that the Energy Star label does in fact automatically implicitly activate positively-valenced associations in individuals familiar with it.
In sum, evidence derived with a variety of implicit methods indicates that ecolabelling can in fact serve to help capture the attention of consumers, as well as to help activate a positive emotional response that might facilitate sustainable purchase preferences. Of course, for such labelling to reliably yield these types of salutary consequences also assumes a careful premarket product research agenda designed to confirm that the labelling itself effectively elicits the affective responses intended by the brand. And to also confirm that the packages such labels are ultimately displayed on are designed in such a way that the ecolabel is depicted in a salient fashion and readily integrated with other types of related information included on the package.
Michael E Smith, PhD is an advisor to CloudArmy and author of ‘Inspiring Green Consumer Choices: Leverage neuroscience to reshape marketplace behavior’ (2021, Kogan-Page, London).
Related:
Sustainable brands AMA with Dr Michael Smith
Behavioral science and sustainability
Sustainability Q&A with Dr Michael Smith
Citations
1. Klaus G, Grunert, K G, Hieke, S, and Wills, J (2014). Sustainability labels on food products: Consumer motivation, understanding and use. Food Policy 44:177–189
2. Kaczorowska, J , Rejman ,K, Halicka, E, Agata Szczebyło, A and Górska-Warsewicz, H (2019). Impact of food sustainability labels on the perceived product value and price expectation of urban consumers. Sustainability, 11:1-17
3. Riskos K, Dekoulou P, Mylonas N, Tsourvakas G. (2021). Ecolabels and the attitude–behavior relationship towards green product purchase: A multiple mediation model. Sustainability13(12):6867. https://doi.org/10.3390/su13126867
4. Quad Packaging & Package Insight (2018) Sustainability packaging and brand image, Part 1: Understanding how sustainable messaging influences consumer decisions. Available at: https://www.quad.com/resources/documents/sustainable-packaging-brand-identity-part-1/ [last accessed August 21, 2020
5. PR Newswire (2018) Consumers don't notice on-pack sustainable messaging, study finds more education needed around sustainability claims. Available at: https://www.prnewswire.com/news-releases/consumers-dont-notice-on-pack-sustainable-messaging-study-finds-more-education-needed-around-sustainability-claims-300635487.html [last accessed August 21, 2020].
6. Proi, M.; Dudinskaya, E.C.; Naspetti, S.; Ozturk, E.; Zanoli, R. The role of eco-labels in making environmentally friendly choices: An eye-tracking study on aquaculture products with Italian consumers. Sustainability 2023, 15, 4659.
7. Jin Jia, Dou Xiaodong, Meng Liang, Yu Haihong (2018) Environmental-friendly eco-labeling matters: Evidences from an ERPs study. Frontiers in Human Neuroscience, 12: DOI=10.3389/fnhum.2018.00417
8. Linder, N S, Uhl, G, Fliessbach, K, Trautner, P, Elger, C E, and Weber, B (2010). Organic labeling influences food valuation and choice. Neuroimage 53: 215–220
9. Enax, L, Krapp, V, Piehl, A, and Weber, B (2015) Effects of social sustainability signaling on neural valuation signals and taste-experience of food products. Frontiers in Behavioral Neuroscience 29:1-15.
10. Greenwald AG, McGhee DE, & Schwartz JLK (1998). Measuring individual differences in implicit cognition: The Implicit Association Test, Journal of Personality and Social Psychology, 74 (6): 1464–1480.
11. Beattie, G., & Sale, L. (2009). Explicit and implicit attitudes to low and high carbon footprint products. The International Journal of Environmental, Cultural, Economic and Social Sustainability, 5:191-206.
12. Beattie, G. & McGuire, L. (2015). Harnessing the unconscious mind of the consumer: How implicit attitudes predict pre-conscious visual attention to carbon footprint information on products. Semiotica, 204, 253-290
13. Waechter S, Sütterlin B, Siegrist M. (2015). Desired and undesired effects of energy labels--An eye-tracking study. PLoS One. 10(7):e0134132.
14. Sawe N, Srirangarajan T, Sahoo A, Tang GS, Knutson B (2022). Neural responses clarify how ecolabels promote sustainable purchases. Neuroimage 263:119668.
15. Fazio, Sanbonmatsu, Powell, & Kardes (1986). On the automatic activation of attitudes. Journal of Personality and Social Psychology, 50, 229–238.
Another such study used functional magnetic resonance imaging (fMRI) to measure differences in brain activity while consumers were evaluating products that were or were not labelled with a highly familiar “organic” logo (8). The food products that were labeled for organic sourcing elicited a greater activation of the Nucleus Accumbens (NAcc) component of the reward network (an area associated with preference and reward anticipation) when they were first presented, and then on average were preferred in choice decisions over alternatives lacking such logos. Moreover, the brain activity differences were observed to be greater in participants who reported greater actual day-to-day organic food consumption, suggesting that the symbols may have been particularly salient and relevant to them.
A similar study examined the impact of “fair-trade” logos on the value the brain calculates for products (9). The researchers found that the highly familiar fairtrade logo increased NAcc activation when they were initially presented. Items which also elicited an increased willingness-to-pay were additionally associated with greater activation of the ventromedial prefrontal cortex, an area reliably activated in processes of involved with subjective valuation. Such results provide compelling evidence that when familiar ecolabels are placed on familiar products, they may in fact help to trigger positive associations and increase engagement in the minds of consumers.
Given the growing awareness that consumer choice has a critical impact on greenhouse gas emissions and potential climate change, there has been a concomitant growth in the number of studies examining how consumers process information about the relative carbon intensity of their purchase behavior, including efforts to better understand the impact of related ecolabelling. The Implicit Association Test (IAT) is a computerized reaction-time based research tool for uncovering automatic associations and motivations (10). One group of researchers (10) examined explicit attitudes to the magnitude of carbon footprints associated with a variety of consumer products (as measured with tools such as feeling thermometer and Likert scale ratings), and contrasted those observations in the same participants with a specialized version of the IAT which compared the categories of high and low carbon footprint products with the attributes ‘good’ and ‘bad’. Overall, both explicit and implicit measures strongly suggested that most participants had more positive feelings towards low carbon footprint products. However, while both types of explicit measures were highly correlated across participants, neither displayed a significant correlation with results from the IAT measure. Which in turn suggests that the IAT was indexing a qualitatively different attitudinal process from that indexed by the explicit tests.
This difference appears to be reflected in the fashion by which individuals respond to carbon footprint ecolabelling on packages. In a follow-up study (12) the researchers combined such explicit and implicit measures of attitudes towards carbon footprint information with eye tracking of the participants whose gaze was monitored while they studied images of product packaging that included carbon footprint information and labelling. In this instance the strength of the implicit positive association towards low carbon footprint products was found to be predictive of how quickly participants first directed their gaze at the carbon footprint package labelling, a relationship that was not observed for either of the explicit attitude measurements. Such results suggest that carbon footprint ecolabelling can capture the attention of consumers (at least those implicitly predisposed to prefer low carbon footprint products), whereas measures of explicitly expressed attitudes about the personal importance of carbon footprints appear to be relatively irrelevant for understanding actual consumer behavior.
Related research has examined how consumers respond to ecolabelling that describes the energy efficiency of consumer electronic products. One such study used eye tracking to better understand the impact of affixing a European Union (EU) mandated energy label to imagery and information describing large household products that consumers were asked to choose among (13). When the energy label was included in the display the researchers found that participants spent more time directly considering energy-related information in the product description, especially when cued to consider energy efficiency as part of their product choice. Despite this overall attention effect, the labelling did not appear to help participants to integrate energy information across the product description or to meaningfully impact product choice, shortcomings that the researchers noted could be perhaps overcome by research on improving the label design and changes in policy efforts to better educate consumers on the information content the labelling seeks to convey.
In the US, the well-known “Energy Star” ecolabel is often affixed to consumer products to convey that the product has been certified to meet minimal efficiency standards set by the US Environmental Protection Agency. Unlike the mandatory EU scheme, whether or not to seek Energy Star labeling is up to the manufacturer, and requires that they demonstrate that products which include such labelling are in fact more energy-efficient than similar products lacking certification. One recent study (14) employed fMRI methods examine the neural responses of study participants while they considered choices between light bulb products with or without Energy Star labeling. As with the fMRI studies of organic and fairtrade labeling described above, the ecolabelled options resulted in greater activation of the NAcc, a type of response typically associated with positive affect and increased purchase intent. The researchers also found that the product/label combinations that elicited greater NAcc activation in the laboratory study were also preferred in a nationwide survey study, suggesting that such labeling might promote sustainable purchases by automatically activating implicit positive emotional responses.
This conclusion is consistent with our own internal research on ecolabelling where we used CloudArmy’s cloud-based ReactorTM reaction time testing platform to conduct an “evaluative priming” study of the Energy Star label. This type of implicit response test is based on the notion that attitudes that have a strong association with an “attitude object” (e.g. a word or picture that represents the target of the attitude) can be automatically activated by presentation of the attitude object (cf. 15). Automatic activation of an attitude can inhibit or facilitate processing of subsequently presented adjectives that have positive or negative connotation. In the study we conducted, responses primed by the Energy Star label were found to be significantly positively associated with such adjectives as “trust”, “efficient” and “for me”. That is, such findings suggest that the Energy Star label does in fact automatically implicitly activate positively-valenced associations in individuals familiar with it.
In sum, evidence derived with a variety of implicit methods indicates that ecolabelling can in fact serve to help capture the attention of consumers, as well as to help activate a positive emotional response that might facilitate sustainable purchase preferences. Of course, for such labelling to reliably yield these types of salutary consequences also assumes a careful premarket product research agenda designed to confirm that the labelling itself effectively elicits the affective responses intended by the brand. And to also confirm that the packages such labels are ultimately displayed on are designed in such a way that the ecolabel is depicted in a salient fashion and readily integrated with other types of related information included on the package.
Michael E Smith, PhD is an advisor to CloudArmy and author of ‘Inspiring Green Consumer Choices: Leverage neuroscience to reshape marketplace behavior’ (2021, Kogan-Page, London).
Related:
Sustainable brands AMA with Dr Michael Smith
Behavioral science and sustainability
Sustainability Q&A with Dr Michael Smith
Citations
1. Klaus G, Grunert, K G, Hieke, S, and Wills, J (2014). Sustainability labels on food products: Consumer motivation, understanding and use. Food Policy 44:177–189
2. Kaczorowska, J , Rejman ,K, Halicka, E, Agata Szczebyło, A and Górska-Warsewicz, H (2019). Impact of food sustainability labels on the perceived product value and price expectation of urban consumers. Sustainability, 11:1-17
3. Riskos K, Dekoulou P, Mylonas N, Tsourvakas G. (2021). Ecolabels and the attitude–behavior relationship towards green product purchase: A multiple mediation model. Sustainability13(12):6867. https://doi.org/10.3390/su13126867
4. Quad Packaging & Package Insight (2018) Sustainability packaging and brand image, Part 1: Understanding how sustainable messaging influences consumer decisions. Available at: https://www.quad.com/resources/documents/sustainable-packaging-brand-identity-part-1/ [last accessed August 21, 2020
5. PR Newswire (2018) Consumers don't notice on-pack sustainable messaging, study finds more education needed around sustainability claims. Available at: https://www.prnewswire.com/news-releases/consumers-dont-notice-on-pack-sustainable-messaging-study-finds-more-education-needed-around-sustainability-claims-300635487.html [last accessed August 21, 2020].
6. Proi, M.; Dudinskaya, E.C.; Naspetti, S.; Ozturk, E.; Zanoli, R. The role of eco-labels in making environmentally friendly choices: An eye-tracking study on aquaculture products with Italian consumers. Sustainability 2023, 15, 4659.
7. Jin Jia, Dou Xiaodong, Meng Liang, Yu Haihong (2018) Environmental-friendly eco-labeling matters: Evidences from an ERPs study. Frontiers in Human Neuroscience, 12: DOI=10.3389/fnhum.2018.00417
8. Linder, N S, Uhl, G, Fliessbach, K, Trautner, P, Elger, C E, and Weber, B (2010). Organic labeling influences food valuation and choice. Neuroimage 53: 215–220
9. Enax, L, Krapp, V, Piehl, A, and Weber, B (2015) Effects of social sustainability signaling on neural valuation signals and taste-experience of food products. Frontiers in Behavioral Neuroscience 29:1-15.
10. Greenwald AG, McGhee DE, & Schwartz JLK (1998). Measuring individual differences in implicit cognition: The Implicit Association Test, Journal of Personality and Social Psychology, 74 (6): 1464–1480.
11. Beattie, G., & Sale, L. (2009). Explicit and implicit attitudes to low and high carbon footprint products. The International Journal of Environmental, Cultural, Economic and Social Sustainability, 5:191-206.
12. Beattie, G. & McGuire, L. (2015). Harnessing the unconscious mind of the consumer: How implicit attitudes predict pre-conscious visual attention to carbon footprint information on products. Semiotica, 204, 253-290
13. Waechter S, Sütterlin B, Siegrist M. (2015). Desired and undesired effects of energy labels--An eye-tracking study. PLoS One. 10(7):e0134132.
14. Sawe N, Srirangarajan T, Sahoo A, Tang GS, Knutson B (2022). Neural responses clarify how ecolabels promote sustainable purchases. Neuroimage 263:119668.
15. Fazio, Sanbonmatsu, Powell, & Kardes (1986). On the automatic activation of attitudes. Journal of Personality and Social Psychology, 50, 229–238.
