How three single-sex Upper East Side schools share programming without merging identities
Quick Answer for Busy Parents
Brearley is considered a sister school of two other Upper East Side institutions: the all-boys Collegiate School and the all-girls Chapin School. The three schools share an after-school program and some classes, giving Brearley students access to coeducational and cross-institutional programming they wouldn’t have at a fully independent single-sex school, without Brearley itself becoming coeducational or merging with either neighbor.
Two Sister Schools, Two Different Relationships
Brearley’s connection to Collegiate and Chapin isn’t identical in both directions. Collegiate, an all-boys school, gives The Brearley School students access to coeducational programming they wouldn’t otherwise have as students at an all-girls school. Chapin, meanwhile, is also all-girls and considered Brearley’s closest peer and rival, a relationship that combines genuine academic camaraderie (shared classes) with the kind of friendly competitive rivalry typical of two similarly excellent schools in the same neighborhood.
Why Maintain Both Relationships?
Keeping a formal relationship with both an all-boys and an all-girls neighboring school gives Brearley students two different kinds of expanded experience: coeducational interaction through Collegiate, and close academic peer relationships through Chapin, rather than only one or the other.
| Sister School | Type | Nature of the Relationship |
| Collegiate School | All-boys | Shared after-school program and some classes |
| The Chapin School | All-girls | Shared after-school program and some classes; also considered Brearley’s closest rival |
The specific shared elements—an after-school program and some classes—mean Brearley students aren’t confined entirely to Brearley’s own building and roster for their full education. A student with a specific academic interest not offered at capacity within Brearley itself may have access to a comparable option through the Collegiate or Chapin partnership, expanding the practical range of what a Brearley education includes beyond what a single 55-to-65-student grade could offer entirely in-house.
Why Stay Single-Sex at All?
Given that The Brearley School already shares meaningful programming with a coeducational partner in Collegiate, families might reasonably ask why the school doesn’t simply become coeducational itself. The arrangement suggests Brearley’s answer: it values the specific benefits of a single-sex classroom environment enough to preserve that structure as the default, while using targeted partnerships to add coeducational and cross-institutional experience on top, rather than folding it into daily classroom life.
A Model That Depends on Geography
None of this works without proximity; Collegiate and Chapin are both nearby on the Upper East Side, making shared after-school programming and classes logistically realistic in a way it wouldn’t be for schools across town from each other.
Curious How Sister-School Programming Fits Your Daughter?
Cardinal Education helps families understand how a school’s cross-institutional partnerships align with a student’s interests.
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Leveraging Brearley’s Sister-School Partnerships
Brearley’s sister-school relationships with Collegiate and Chapin offer students unique coeducational and cross-institutional opportunities while preserving the school’s core single-sex identity. Because specific shared classes and offerings evolve annually, Cardinal Education helps families strategically evaluate how these partnerships align with your daughter’s academic goals.
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