Preserving His Reputation: As the minister of Salem's Puritan community, Parris is acutely aware of the importance of reputation and social standing. Betty's strange behavior and the rumors of witchcraft surrounding her threaten to tarnish his image and undermine his authority within the community. By expressing concern and taking action to "cure" Betty, Parris aims to protect his own reputation and maintain his position of power.
Fear of the Unknown: The Puritan society of Salem is deeply religious, and the concept of witchcraft is a serious and terrifying matter. Parris, like many others in the community, genuinely fears the potential presence of witchcraft and the harm it can bring. His concern for Betty is partly driven by this fear and his desire to protect his family and the community from evil.
Avoiding Responsibility: By focusing on Betty's condition and the possibility of witchcraft, Parris can divert attention away from his own shortcomings as a minister and the broader problems within the community. He can blame Betty's affliction on external forces rather than acknowledging any internal issues or conflicts that may be contributing to the community's troubles.
While Parris' concern for Betty is genuine to some extent, it is also intertwined with his self-interest and his desire to maintain his position in the community. These underlying motives shape his actions and decisions throughout Act I and contribute to the escalating conflict in the play.