Yes, you can! When reading messages in "List as Individual Messages" View, Groups provides you with 3 different views within the Messages page, depending upon your individual preference.

• Simple: Shows only the subject lines. This is the most compact view.
• Summary: Shows the subject line and the first part of the message. You can use this to quickly scan the conversation.
• Expanded: Shows each of the messages in full form, on top or each other.

When you change your viewing options, they are remembered for your subsequent visit, so you shouldn't have to set them again.

(Note: preferences are set on your browser and expire after seven days. As long as you visit the site at least once every seven days, using the same browser, you should not need to reset your preferences).