 Christine Nicholl suggested that there hadn't actually been enough studies to conclusively prove a substantial improvement in welfare with slower-growing birds. We have to be very careful that they're not just living a little bit longer but ending up having the same problems towards the very end of their life. So we need to do fair comparisons, and there haven't been very many studies done. Of course, even between scientific studies and science-backed campaigns, you do find a difference of opinions.