In some cases, you may not wish to ask your users to re-authenticate when those users attempt to log in with multiple social accounts or with a traditional and social account. This may be the case if you have pre-created accounts for users or if your users are prone to logging in infrequently.
By default, if Registration detects that a user is logging in with a new social account, it will request that the user re-authenticate with his or her original account and new account in order to merge the two accounts. You may enable Registration to bypass this process, automatically merging the two accounts through a “silent merge”. The bypass will work only if both the user’s accounts return an email validated by the provider as belonging to the authenticated user.
To enable this feature:
https://dashboard.janrain.com), click the database icon, and click the Settings tab.