a. Fig. 2A, preference for larger reward | *z* tests (50% preference; one-tailed); ANOVA (% difference in compared BSR frequencies) | *p* < 0.001 (25–100% difference in BSR)**F*_{(3,45)} = 13.1, *p* < 0.001* | *p*’s<0.001 (25-100% difference in BSR)**F*_{(3,45)}=13.1, *p*<0.001* |

b. Fig. 2B, preference for larger reward | *z* tests (50% preference; one-tailed); ANOVA (individual frequency comparisons) | *p* < 0.05 (all BSR comparisons)**F*_{(10,118)} = 6.995, *p* < 0.001* | *p*’s<0.05 (all BSR comparisons)**F*_{(10,118)}=6.995, *p*<0.001* |

c. Fig. 2C, preference for larger reward | *z* tests (50% preference; one-tailed); ANOVA (raw difference in compared BSR frequencies) | all *p* < 0.001 (all BSR comparisons)**F*_{(5,37)} = 3.61, *p* = 0.011* | all *p*’s<0.001 (all BSR comparisons)**F*_{(5,37)}=3.61, *p*=0.011* |

d. Fig. 2D, number of trials completed | ANOVA (individual frequency comparisons) | *F*_{(10,118)} = 2.446, *p* = 0.011* | *F*_{(10,118)}=2.446, *p*=0.011* |

e. Fig. 2E, preference for larger reward | *z* tests (50% preference; one-tailed); ANOVA (proportionate time × % difference in BSR frequency); ANOVA (proportionate time); ANOVA (% difference in BSR frequency) | *p* ≤ 0.01 (all BSR comparisons)**F*_{(27,279)} = 1.346, *p* = 0.133*F*_{(9,279)} = 5.838, *p* < 0.001**F*_{(3,279)} = 20.582, *p* < 0.001* | *p*’s≤0.01 (all BSR comparisons)**F*_{(27,279)}=1.346, *p*=0.133*F*_{(9,279)}=5.838, *p*<0.001**F*_{(3,279)}=20.582, *p*<0.001* |

f. Fig. 2F, number of trials completed | ANOVA (proportionate time × % difference in BSR frequency); ANOVA (proportionate time); ANOVA (% difference in BSR frequency) | *F*_{(27,279)} = 1.242, *p* = 0.205*F*_{(9,279)} = 6.320, *p* < 0.001**F*_{(3,279)} = 1.457, *p* = 0.259 | *F*_{(27,279)}=1.242, *p*=0.205*F*_{(9,279)}=6.320, *p*<0.001**F*_{(3,279)}=1.457, *p*=0.259 |

g. Fig. 3A, preference for larger reward | *z* tests (50% preference; one-tailed); ANOVA (difference in pellet number) | *p* < 0.001 (all pellet comparisons)**F*_{(3,39)} = 8.63, *p* < 0.001* | *p*’s<0.001 (all pellet comparisons)**F*_{(3,39)}=8.63, *p*<0.001* |

h. Fig. 3B, preference for larger reward | *z* tests (50% preference; one-tailed); ANOVA (individual pellet comparisons within each comparison range) | *p* < 0.001 (1v2, 2v3, 1v3, 2v4, 1v4, 2v5, 1v5)**F*_{(10,118)} = 7.00, *p* < 0.001* | *p*’s<0.001 (1v2, 2v3, 1v3, 2v4, 1v4, 2v5, 1v5)**F*_{(10,118)}=7.00, *p*<0.001* |

i. Fig. 3C, number of trials completed | ANOVA (individual pellet comparisons within each comparison range) | *F*_{(10,109)} = 5.40, *p* < 0.001* | *F*_{(10,109)}=5.40, *p*<0.001* |

j. Fig. 3D, number of trials completed | Pearson correlation | *R*
^{2} = 0.998, *p* < 0.0001* | R^{2}=0.998, *p*<0.0001* |

k. Fig. 3E, preference for larger reward | *z* tests (50% preference; one-tailed); ANOVA (proportionate time × % difference in pellet number); ANOVA (proportionate time); ANOVA (% difference in pellet number) | *p* ≤ 0.05 (0.0–0.1 proportionate time)**F*_{(27,399)} = 1.509, *p* = 0.056*F*_{(9,399)} = 25.29, *p* < 0.001**F*_{(3,399)} = 1.91, *p* = 0.152 | *p*≤0.05 (0.0-0.1 proportionate time)**F*_{(27,399)}= 1.509, *p*=0.056*F*_{(9,399)}= 25.29, *p*<0.001**F*_{(3,399)}= 1.91, *p*=0.152 |

l. Fig. 3F, number of trials completed | ANOVA (proportionate time × difference in pellet number); ANOVA (proportionate time); ANOVA (% difference in pellet number) | *F*_{(27,399) =} 0.878, *p* = 0.64*F*_{(9,399) =} 112.136, *p* < 0.001**F*_{(3,399) =} 1.146, *p* = 0.349 | *F*_{(27,399)=}0.878, *p*=0.64*F*_{(9,399)=}112.136, *p*<0.001**F*_{(3,399)=}1.146, *p*=0.349 |

m. Fig. 4A, preference for 1 sugar pellet | *z* test (50% preference; one-tailed); ANOVA (proportionate BSR frequency) | *p* < 0.05 (0%, 50% BSR)**F*_{(4,24)} = 0.413, *p* = 0.80 | *p*’s<0.05 (0%, 50% BSR)**F*_{(4,24)}=0.413, *p*=0.80 |

n. Fig. 4B, preference for 2 sugar pellets | *z* test (50% preference; one-tailed); ANOVA (proportionate BSR frequency) | *p* < 0.001 (0%, 25% BSR)**F*(_{4,24)} = 0.963, *p* = 0.449 | *p*’s<0.001 (0%, 25% BSR)**F*(_{4,24)}=0.963, *p*=0.449 |

o. Total pellets earned | ANOVA (sugar pellet reward size × BSR reward size); ANOVA (sugar pellet reward size); ANOVA (BSR reward size) | *F*_{(4,49)} = 1.486, *p* = 0.253*F*_{(1,49)} = 66.31, *p* < 0.001**F*_{(4,49)} = 1.037, *p* = 0.418 | *F*_{(4,49)}=1.486, p=0.253*F*_{(1,49)}=66.31, *p*<0.001**F*_{(4,49)}=1.037, p=0.418 |

*p*. Fig. 4C, preference for 1 sugar pellet | *z* test (50% preference; one-tailed); ANOVA (proportionate time × proportionate BSR frequency); ANOVA (proportionate time); ANOVA (proportionate BSR frequency) | all *p* < 0.05 (0.3–1.0 proportionate time)**F*_{(36,249)} = 0.928, *p* = 0.59*F*_{(9,249)} = 3.987, *p* = 0.001*F*_{(4,249)} = 0.82, *p* = 0.531 | all *p*’s<0.05 (0.3-1.0 proportionate time)**F*_{(36,249)}=0.928, *p*=0.59*F*_{(9,249)}=3.987, *p*=0.001*F*_{(4,249)}=0.82, *p*=0.531 |

q. Fig. 4D, preference for 2 sugar pellets | *z* test (50% preference; one-tailed); ANOVA (proportionate time × proportionate BSR frequency); ANOVA (proportionate time); ANOVA (proportionate BSR frequency) | all *p* < 0.05 (0.6–1.0 proportionate time)**F*_{(36,249)} = 1.886, *p* = 0.005**F*_{(9,249)} = 10.60, *p* < 0.001**F*_{(4,249)} = 1.295, *p* = 0.314 | all *p*’s<0.05 (0.6-1.0 proportionate time)**F*_{(36,249)}=1.886, *p*=0.005**F*_{(9,249)}=10.60, *p*<0.001**F*_{(4,249)}=1.295, *p*=0.314 |

r. Fig. 4E, number of trials completed (1-pellet sessions) | ANOVA (proportionate time × proportionate BSR frequency); ANOVA (proportionate time); ANOVA (proportionate BSR frequency) | *F*_{(36,249)} = 0.916, *p* = 0.608*F*_{(9,249)} = 3.353, *p* = 0.004**F*_{(4,249)} = 1.538, *p* = 0.239 | *F*_{(36,249)}=0.916, *p*=0.608*F*_{(9,249)}=3.353, *p*=0.004**F*_{(4,249)}=1.538, *p*=0.239 |

s. Fig. 4F, number of trials completed (2-pellet sessions) | ANOVA (proportionate time × proportionate BSR frequency); ANOVA (proportionate time); ANOVA (proportionate BSR frequency) | *F*_{(36,249)} = 1.360, *p* = 0.105*F*_{(9,249)} = 4.673, *p* < 0.001**F*_{(4,249)} = 0.606, *p* = 0.664 | *F*_{(36,249)}=1.360, *p*=0.105*F*_{(9,249)}=4.673, *p*<0.001**F*_{(4,249)}=0.606, *p*=0.664 |