## 1 Introduction  
The growth in robot applications has led to human-robot interactions (HRI) in many different areas such as industry [1] and healthcare [2]. These HRI applications can take place in the form of physical interactions (e.g., exoskeleton support [3]) or social interactions (e.g., health support, customer service [4]). Social robots can be defined as robots that employ social interactions to meet the needs of its human users [5]. They can be used for applications such as companionship [6] and as a therapeutic device [7]. The goal of these robots is to improve people's quality of life [8]. An important factor in reaching this goal is the robot's ability to interact more reliably, intuitively and naturally with people. Expressing artificial emotions during interactions can be an asset, as it has been found to increase the use of the robot, resulting in people being able to fully benefit from the services that the robot provides [9]. The expression of artificial emotion can also build empathy and induce trust [10], which is a factor in the acceptance of social robots [11]. Interactions with robots reach beyond the scope of human-robot interactions, for example, animal-robot interactions (e.g., [12, 13, 14, 15]). This work focuses specifically on older adults as they are particularly likely to benefit from social robots [16] due to the increase in loneliness [17] and health issues [18] as people live longer. However, the likelihood of negative consequences during human-robot interactions (HRI) may also be greater for older adults due to age-related impairments that might result in a higher level of vulnerability [19, 20]. Ethical concerns have been expressed in robot ethics literature, not only focusing on the impact of social robots but human-robot collaborations in general. Example concernsinclude the loss of privacy, loss of control, infantilisation, attribution of responsibility, loss of human contact, emotional deception, and emotional attachment [19; 21; 22; 23; 24; 25; 26]. Furthermore, these concerns not only apply to the people directly interacting with the robot but also to others that are engaged in improving the quality of life for these people [27; 28]. Many principles and frameworks have been published to address ethical concerns in robotics and Artificial Intelligence [29]. However, even though these concerns have been raised in the literature, they are often not investigated and analysed further as part of real-world trials and studies [30]. Due to the lack of real-world studies in this area, it should not be assumed that all the obstacles and ethical concerns are known [28]. We aim to address this by investigating ethical concerns of social robots that express artificial emotions through human-robot interaction experiments. A long-term human-robot interaction study was conducted with older adults to investigate the occurrence and impact of emotional deception and emotional attachment. In this study, participants' experiences when interacting with a robot that displayed artificial emotions was compared with their experiences when interacting with a robot that did not display emotions. This study provided rich insights on user experiences, highlighting potential negative consequences of expression of artificial emotions by a social robot during human-robot interactions. This study has been described in prior work [31]; thus, an overview will be presented here to provide context for the insights made regarding the use of HRI research to investigate robot ethics. The main contributions from this paper consist in using the findings from this research to further investigate robot ethics and raise the fundamental question of whether we should continue to develop these robots if we cannot sufficiently investigate their impact or if we should shift the focus of our research to include the development of HRI assessment tools that can help us do so. The next section provides a background on emotional deception and emotional attachment and discusses why they are ethical concerns.